[0001] The present disclosure relates to a field of networking infrastructure and in particular, relates to a system and method for enabling dynamic bandwidth control in a passive optical network infrastructure. The present application is based on, and claims priority from an Indian Application Number 202011011593 filed on 18th March 2020, the disclosure of which is hereby incorporated by reference herein.

BACKGROUND
[0002] Over the last few decades, a network infrastructure has flourished at very rapid pace. The network infrastructure plays a significant role in development of any country. In addition, the network infrastructure includes hardware and software resources that enable network connectivity, communication, operations and management of an enterprise network. Further, passive optical network (PON) is an essential part of the network infrastructure. The PON provides network access to end customers. Furthermore, the PON includes optical line terminal (OLT) at central office, optical network units (ONUs) at premises of end customers, and optical distribution network (ODN) connecting the OLT and the ONUs. In recent years, gigabit passive optical network (GPON) using time division multiplexing (TDM) are deployed widely for residential customers while wavelength division multiplexing (WDM) PONs are deployed in those premises which has high bandwidth hungry applications . The capacity of GPON port is limited to 2.5 gigabits per second and 1.25 gigabits per second in downstream and upstream directions, respectively due to hardware constraint while the XGSPON, also called as 10G symmetric PON is being seen as a commercial viable solution for high capacity PON applications. Further, the PON requires dynamic bandwidth management solutions. Furthermore, present bandwidth management solutions for the PON fall short of addressing above hardware constraints, thereby limiting the accessible bandwidth/subscriber to port speeds of PON port interface in upstream direction. Also, the present bandwidth management solutions for the PON are rigid, cost ineffective and at times, require human interventions.
[0003] In light of the above stated discussion, there is a need for a system that overcomes the above stated limitations.

OBJECT OF THE DISCLOSURE
[0004] A primary object of the present disclosure is to provide a method and a system for handling dynamic bandwidth allocation in a passive optical network infrastructure by dynamic allocation of PON ports based on a logical grouping of PON ports. When a subscriber group among a plurality of subscriber groups associated with at least one PON port requires a bandwidth upgrade in excess of PON port capacity, the excess traffic originating from the subscriber group is shifted from a first wavelength to a second wavelength associated with a second PON port in an optical line terminal (OLT). The excess traffic is shifted by wavelength tuning at the ONU and wavelength selective switch (WSS) at the OLT. This results in providing a dynamic quality of service (QoS) passive optical network infrastructure.
[0005] Another object of the present disclosure is to provide a system to increase scale and capacity of passive optical network infrastructure without duplication of hardware resources.
[0006] Yet another object of the present disclosure is to provide the system to enable dynamic and isolated re-use of capacity allocation of passive optical network infrastructure.
[0007] Yet another object of the present disclosure is to provide the system that allows internet service providers to support multi-tenancy.
[0008] Yet another object of the present disclosure is to provide the system to support 1:N Type-B passive optical network port protection.
[0009] Yet another object of the present disclosure is to provide the system to offer dynamic scaling of upstream bandwidth.
[0010] Yet another object of the present disclosure is to provide the system for enabling scaling of upstream bandwidth beyond PON port speed.
SUMMARY
[0011] In an aspect, the present disclosure provides a method for handling dynamic bandwidth allocation in a passive optical network. The method includes receiving, by a dynamic bandwidth management system, a request to adjust a bandwidth from at least one subscriber among a plurality of groups. Further, the method includes sending, by the dynamic bandwidth management system, the request to a software-defined networking (SDN) controller to adjust a bandwidth profile of the at least one subscriber among the plurality of groups. Further, the method includes determining, by the dynamic bandwidth management system, a bandwidth usage of each of a PON port at an optical line terminal and a quality of service (QoS) of other subscribers among the plurality of groups. Further, the method includes switching one or more subscribers associated with at least one PON port on the optical line terminal to another available PON port based on the determination.
[0012] In another aspect, the current disclosure provides switching of subscribers associated with the at least one PON port on the optical line terminal to another available PON port based on the SDN controller decision that includes tuning a wavelength of upstream carrier of the subscriber to another wavelength, wherein the another wavelength is associated with the available PON port and logically grouped with a current PON port, adjusting a filter wavelength of an output port of a wavelength selective switch based on the tuned wavelength at the OLT, and switching other subscribers associated with the at least one PON port on the optical line terminal to another available PON port in response to adjusting the filter wavelength of the output port of the wavelength selective switch.
[0013] The wavelength of upstream carrier is in range of 1270 nm to 1330 nm, in the case of XGSPON and GPON, respectively.
[0014] The filter bandwidth is in range of 1 GHz to tens of GHz to 100 of GHz.
[0015] The subscribers requesting for bandwidth adjustment or scaling of bandwidth, associated with the at least one PON port on the optical line terminal are switched to another available PON port through tuning of upstream wavelength bandwidth without physically disconnecting the at least one PON port associated with other subscribers.
[0016] In another aspect, the present disclosure provides a passive optical network for handling dynamic bandwidth allocation. The passive optical network includes one or more programmable wavelength selective switch connected with an optical line terminal, an SDN controller controlling configuration of the one or more programmable wavelength selective switch, and one or more optical network units (ONUs) connected with the optical line terminal via the one or more programmable wavelength selective switch. The SDN controller comprises a dynamic bandwidth management system. The dynamic bandwidth management system is configured to receive a request to adjust a bandwidth from at least one subscriber among a plurality of groups and send the request to the SDN controller to adjust a bandwidth profile of the at least one subscriber among the plurality of groups. The dynamic bandwidth management system is configured to determine a bandwidth usage of each of a PON port at the optical line terminal and a QoS of other subscribers among the plurality of groups. Further, the dynamic bandwidth management system is configured to switch other subscribers associated with the at least one PON port on the optical line terminal to another available PON port based on the determination.

STATEMENT OF THE DISCLOSURE
[0017] In an aspect, the present disclosure provides a system and method for enabling dynamic bandwidth control in passive optical network infrastructure. The method includes receiving a request to adjust the bandwidth from at least one subscriber among a plurality of groups. The method includes sending the request to an SDN controller to adjust a bandwidth profile of the at least one subscriber among the plurality of groups. The method includes determining the bandwidth utilization at each of the PON ports of optical line terminal and a QoS requirements of other subscribers among the plurality of groups. The method includes tuning a wavelength of upstream carrier of the subscriber to another wavelength, within an allocated upstream wavelength band. The new wavelength is associated with the available PON port and logically grouped with a current PON port. The method includes adjusting a filter wavelength of an output port of a wavelength selective switch based on the tuned wavelength at the OLT. The method includes switching other subscribers associated with the at least one PON port on the optical line terminal to another available PON port in response to adjusting the filter wavelength of the output port of the wavelength selective switch.
[0018] The method can be used to handle the dynamic bandwidth allocation in the passive optical network infrastructure by dynamic allocation of PON ports based on a logical grouping of PON ports. Each PON port is allocated a narrow band within the downstream and upstream wavelength band of the PON system. In another aspect, each PON port may be allocated a wavelength. When a subscriber group requires more bandwidth, excess traffic is shifted from a first wavelength to a second wavelength, so that the method can be used to shift excess traffic from a first PON port to a second PON port in an OLT using wavelength tuning at the ONU and wavelength selective switch (WSS) at the OLT. This results in providing a dynamic quality of service (QoS) passive optical network infrastructure. The method can be used to increase scale and capacity of passive optical network infrastructure without duplication of hardware resources. The method can be used to enable dynamic and isolated re-use of capacity allocation of passive optical network infrastructure. The method may allow/enable internet service providers to support multi-tenancy and offer dynamic scaling of upstream bandwidth.
[0019] Further, the proposed method can be used to handle seamless movement of subscribers on the optical network unit between PON ports of optical line terminal (OLT). The proposed method can be used to support dynamic 1:N Type-B protection of ONU/Ts connected to the PON port, where a single PON port is reserved for Type-B protection of ‘N’ active PON ports. In the proposed methods, an optical layer slicing supports multi-tenant sharing of same physical access network infrastructure. In other words, the proposed method can be used to decouple the subscribers (ONU/Ts) connected to the PON port and seamlessly switch subscribers (ONU/Ts) between PON ports. In other words, the proposed method can be used to enable network providers to support multi tenancy (multiple service providers can share same optical access network) by optical layer slicing.

BRIEF DESCRIPTION OF FIGURES
[0020] The method and system are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0021] FIG. 1 shows a traditional PON architecture.
[0022] FIG. 2 shows another example of the traditional PON architecture.
[0023] FIG. 3 illustrates an interactive computing environment for enabling dynamic bandwidth control in passive optical network over a Fibre-to-the-x (FTTx) network infrastructure.
[0024] FIGS. 4-7 are example illustrations of various PON architectures in which dynamic bandwidth allocation is explained.
[0025] FIG. 8 illustrates a flowchart for enabling dynamic bandwidth control in passive optical network over the Fibre-to-the-x (FTTx) network infrastructure.
[0026] FIG. 9 illustrates a block diagram of a computing device.
[0027] It should be noted that the accompanying figure is intended to present illustrations of exemplary embodiments of the present disclosure. This figure is not intended to limit the scope of the present disclosure. It should also be noted that accompanying figure is not necessarily drawn to scale.

DETAILED DESCRIPTION
[0028] In the following detailed description of embodiments of the invention, numerous specific details are set forth in order to provide a thorough understanding of the embodiment of invention. However, it will be obvious to a person skilled in the art that the embodiments of the invention may be practiced with or without these specific details. In other instances, well known methods, procedures and components have not been described in details so as not to unnecessarily obscure aspects of the embodiments of the invention.
[0029] Furthermore, it will be clear that the invention is not limited to these embodiments only. Numerous modifications, changes, variations, substitutions and equivalents will be apparent to those skilled in the art, without parting from the scope of the invention.
[0030] The accompanying drawings are used to help easily understand various technical features and it should be understood that the embodiments presented herein are not limited by the accompanying drawings. As such, the present disclosure should be construed to extend to any alterations, equivalents and substitutes in addition to those which are particularly set out in the accompanying drawings. Although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are generally only used to distinguish one element from another.
[0031] It should be noted that the terms "first", "second", and the like, herein do not denote any order, ranking, quantity, or importance, but rather are used to distinguish one element from another. Further, the terms "a" and "an" herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.
[0032] In order to facilitate an understanding of the inventive concept, prior art techniques will first be discussed with reference to FIGS. 1-2. FIG. 1 represents conventional GPON/XGSPON based passive optical network architecture, where GPON/XSPON ONU’s are attached to GPON/XGSPON OLT using optical distribution network, respectively. The downstream (DS) and upstream (US) bit rates of GPON are set to 2.5Gbps and 1.25 Gbps, respectively, while the DS and US bit rates of XGSPON are set to 10Gbps in both directions.
[0033] FIG. 1 shows a traditional PON architecture with multiple subscriber groups (enterprise, customer premise equipment (CPE)) connected to individual proprietary ONUs and hardwired to proprietary OLTs, connected with switches. Drawbacks are that the architecture uses proprietary components and the software stack of the proprietary components is not open to operators. Hardwiring of OLT PON ports with subscriber groups results in inefficient use of PON port capacities.
[0034] FIG. 2 shows another example of the traditional PON architecture that uses Open white box components such as Open ONUs, Open OLTs and connected with a SDN controller. The SDN controller configures the OLTs, the ONUs and any other white box switches attached to the controller. The software stack of the SDN controller can run on any general purpose x86 server. The optical layer in this architecture, which connects subscriber (“Residential Gateway”) with OLTs through ONUs, uses hardwired connections. The optical layer is not programmable which does not allow scaling of upstream bandwidth for subscriber beyond hardwired PON port capabilities or speed. Drawback of the system is that it does not allow optimum usage of PON ports at OLTs. Hardwiring of the PON port with subscribers does not allow sharing of PON ports of OLTs by the subscriber groups.
[0035] Conventionally, a single ONT (Optical Network Terminal) is allowed to transmit data at a given point in time in a shared upstream channel. A bandwidth allocation technique determines a start time and length of a transmission time slot for each ONT. Further, statistical multiplexing of network traffic in access networks can be exploited using a Dynamic Bandwidth Algorithm (DBA). The DBA process contains three important steps as follows: calculation of bandwidth demand for the T-CONTs (logical queue at the ONT associated with specific QoS requirements) based on a segment routing (SR) or traffic monitoring (TM) information, assignment of bandwidth based on service and fair-share policies and scheduling of the upstream traffic through the construction of upstream bandwidth maps. In the DBA, the following are the limitation (i.e., due to hardware constraint, the PON port capacity is limited to 1.25G and 10G for GPON and XGSPON, and upstream bandwidth of subscribers beyond certain bandwidth (1.25G/10G) is not possible due to the hardware constraint.
[0036] FIG. 3 illustrates an interactive computing environment (alternatively referred to as a system) 100 for enabling dynamic bandwidth control in a passive optical network over a Fibre-to-the-x (FTTx) network infrastructure. In general, the FTTx is a term used for any broadband network architecture using optical fibre to provide all or part of local loop used for last mile telecommunications. In addition, the optical fibre is a thin fibre of glass or plastic that can carry light from one end to the other. Further, the optical fibre is mainly used in telecommunications and networking. Furthermore, the optical fibre is used for lighting, sensors, toys, and special cameras for seeing inside small spaces.
[0037] In general, the FTTx stands for Fibre-to-the-x or Fibre-to-the-loop. In addition, the FTTx is a generalization for various configurations of fibre deployment. Further, the various configurations of fibre deployment includes a first configuration and a second configuration. Furthermore, the first configuration includes but may not be limited to a FTTP, a FTTH and a FTTB. The FTTP stands for Fibre to the Premises. The FTTH stands for Fibre to the Home. The FTTB stands for Fibre to the Building. The second configuration includes but may not be limited to a FTTC and a FTTN. The FTTC stands for Fibre to the Cabinet. The FTTN stands for Fibre to the Node. However, the various configurations of fibre deployment are not limited to above mentioned configurations.
[0038] In an aspect of the present disclosure, the interactive computing environment 100 enables dynamic bandwidth control in the passive optical network over the FTTx network infrastructure. The passive optical network (PON) may comprise an optical fiber network for transmitting data between a single transmission point and a plurality of end users. The dynamic bandwidth control allows allocation of traffic bandwidth in shared telecommunications medium on demand of users. In addition, the dynamic bandwidth control is a form of bandwidth management. Further, the dynamic bandwidth control adapts to instantaneous traffic demands of the users. Furthermore, the dynamic bandwidth control enables seamless switching of the users because typically all users are not connected to network at one time. In general, the PON is a telecommunications technology used to provide optical fibre to end consumer, both domestic and commercial. In addition, the optical line terminal performs conversion between electrical signals used by service provider's equipment and fibre optic signals used by the PON. Further, the optical line terminal coordinates multiplexing between conversion devices on another end of network. The conversion devices include but may not be limited to optical network terminals (ONTs) and optical network units (ONUs)
[0039] The interactive computing environment 100 demonstrates working of a dynamic bandwidth management system 120 with a programmable optical layer to dynamically allocate bandwidth and to enable scaling of upstream bandwidth in the PON. The dynamic bandwidth management system 120 can be a Device Subscriber Management (DSM) component. In addition, the dynamic bandwidth management system 120 delivers dynamic QoS. Further, the dynamic bandwidth management system 120 scales the bandwidth capacity in the PON. Furthermore, the dynamic bandwidth management system 120 supports 1:N Type-B passive optical network port protection. For example, in the case of 1:1 Type-B protection, for every PON port there is another dedicated PON port on OLT reserved as backup to overcome PON port failure. But in the case of 1:N Type B protection, only one PON port is reserved as backup for ‘N’ active PON ports of OLT. With the incorporation of WSS at central office, the current architecture offers flexibility to switch traffic from any PON port of OLT to any PON port reserved for failure protection. The current architecture can also distribute the load of the failed PON port over the other active PON ports of OLT. The current architecture achieves the type-B PON port protection without the need for additional fiber protection/standby link in the PON system.
[0040] The dynamic bandwidth allocation in the PON may be the allocation of bandwidth from the PON to the plurality of end users based on end user requirements. The end user requirements may comprise at least one request from at least one subscriber for the bandwidth to facilitate at least one application. The dynamic bandwidth allocation may be performed by checking of a bandwidth usage availability at a plurality of PON ports at an optical line terminal (OLT). The plurality of PON ports may be one or more interfaces at the optical line terminal for handling communication between the at least one subscriber and the optical line terminal in the PON. The technique involved in the dynamic bandwidth allocation is explained below in detail.
[0041] The interactive computing environment 100 includes a subscriber group 102, an optical network unit 104, a tunable optical transceiver 106, and an optical power splitter 108. In addition, the interactive computing environment 100 includes a central office 110, a software-defined network (SDN) controller 112, a wavelength selective switch (WSS) 114, an optical line terminal 116, and a fabric switch 118. The interactive computing environment 100 provides programmable optical layer in the FTTx network infrastructure for the subscriber group 102.
[0042] The subscriber group 102 may include, but not be limited to, residential, enterprises, wireless mobile base station, and Multi-national Corporations. In addition, the subscriber group 102 may include a plurality of users. In general, the users include users in a business, users in building, users in home, users in a premise, and the like. Each of the plurality of users may be any person or individual accessing corresponding communication device of one or more communication devices. In an aspect of the present disclosure, the plurality of users is owner of the one or more communication devices. In another aspect of the present disclosure, the plurality of users is not the owner of the one or more communication devices. In an aspect of the present disclosure, the plurality of users accesses the one or more communication devices at home. In another aspect of the present disclosure, the plurality of users accesses the one or more communication devices at a cafe. In yet another aspect of the present disclosure, the plurality of users accesses the one or more communication devices at office. In an example, a user U1 accesses a smartphone S1 while sitting in a living room. In another example, a user U2 accesses a laptop L2 while travelling from one place to another. In yet another example, a user U3 accesses a desktop computer D3 while working at office.
[0043] The plurality of users is connected with the interactive computing environment 100 through the one or more communication devices. In an aspect of the present disclosure, each of the one or more communication devices is a portable communication device. The portable communication device includes but may not be limited to a laptop, smartphone, tablet, virtual reality device, internet of things device, and smart watch. In an example, the smartphone may be an iOS-based smartphone, an android-based smartphone, a windows-based smartphone and the like. In another aspect of the present disclosure, each of the one or more communication devices is a fixed communication device. The fixed communication device includes but may not be limited to desktop, workstation, smart TV and mainframe computer. In an aspect of the present disclosure, the plurality of users accesses the one or more communication devices in the subscriber group 102.
[0044] In an aspect of the present disclosure, the subscriber group 102 includes the optical network unit 104 and a residential gateway. In general, the optical network unit 104 converts optical signals transmitted through fibre to electrical signals. In addition, the electrical signals are sent to subscribers. Further, the optical network unit 104 sends, aggregates and grooms data coming from the subscribers. In an aspect of the present disclosure, the optical network unit 104 send data upstream to the optical line terminal 116. In addition, the optical network unit 104 optimises and reorganises the data stream coming from the plurality of users. Further, the optical line terminal 116 supports bandwidth allocation to smooth data delivery flow to the optical network unit 104. Furthermore, the optical network unit 104 is connected through various units. The various units include but may not be limited to twisted-pair copper wire, coaxial cable, single optical fibre or multi-mode optical fibre.
[0045] In general, the residential gateway is a consumer-grade router that provides network access between local area network (LAN) hosts to wide area network (WAN) through a modem. In addition, the modem is integrated with hardware of the residential gateway. Further, the WAN is larger computer network that is operated by Internet service provider. In an aspect of the present disclosure, the residential gateway includes but may not be limited to Cable modem, DSL modem, Wireless router, Network switch, and IP-DECT telephone (base station). In another aspect of the present disclosure, the residential gateway includes but may not be limited to Voice over internet protocol (VoIP) analog telephone adapter. Wireless access point, and Wired router.
[0046] The dynamic bandwidth management system 120 receives a request from a first subscriber of the subscriber group 102 for a predefined bandwidth allocation. The first subscriber may be a single subscriber or a group of subscribers connected to the optical network unit (ONU) 104, which is further connected to the optical line terminal (OLT) 116 at the central office 110. The first subscriber may be at least one subscriber, corresponding to the subscriber group. The first subscriber may be a first subscriber group, the first subscriber group may be having a plurality of subscribers. For example, a plurality of subscribers in a particular zone or building may be considered as the first subscriber. Similarly, a single subscriber may be termed as the first subscriber. Further, the bandwidth is maximum rate of data transfer. The bandwidth is characterized as network bandwidth, data bandwidth, or digital bandwidth. In an aspect of the present disclosure, the group is any residential end-subscriber. In another aspect of the present disclosure, the group is any enterprise end-subscriber. In yet another aspect of the present disclosure, the group is any wireless mobile base station. In yet another aspect of the present disclosure, the group is any suitable end-subscriber.
[0047] The dynamic bandwidth management system 120 sends the request received from the first subscriber to the SDN controller 112. In addition, the dynamic bandwidth management system 120 allows the SDN controller 112 to analyse bandwidth consumption and the QoS of other subscribers. The SDN controller may determine a bandwidth consumption and a quality of service (QoS) of other subscribers in the subscriber group from a plurality of subscriber groups. The SDN controller may decide, if the request to adjust bandwidth from the at least one subscriber is to be processed for allocation based on at least one of: subscription of the first subscriber, determination of bandwidth consumption and the QoS requirements of the other subscribers in the subscriber group.
[0048] That is, the SDN controller 112 in the interactive computing environment 100 receives the request from the first subscriber for the predefined bandwidth to facilitate a service. Upon receiving the request for bandwidth, the SDN controller 112 checks bandwidth availability at the plurality of PON ports associated with the OLT and selects a sub-plurality of PON ports where the bandwidth availability is more than the predefined bandwidth. The SDN controller 112 then selects a second PON port from the plurality of PON ports for switching the first subscriber from a first PON port to the second PON port. Accordingly, the SDN controller 112 performs allocation of bandwidth using available bandwidth corresponding to the plurality of PON ports of the OLT 116. The plurality of PON ports at the OLT 116 may be used by the first subscriber using logical binding of the plurality of PON ports with the first subscriber. This may further mean that there may be no hard wiring of a PON port with the first subscriber.
[0049] The SDN controller 112 allocates the predefined bandwidth to the first subscriber by the second PON port, when a first bandwidth availability at the first PON port is less than the predefined bandwidth and a second bandwidth availability at the second PON port is more than the predefined bandwidth. In an implementation, a portion of the second bandwidth availability is allocated to the first subscriber.
[0050] That is, the predefined bandwidth required by the first subscriber is allocated by the second PON port, if there may be no sufficient available bandwidth at the first PON port, which is connected to the first subscriber (first subscriber group). In this case, the allocation of bandwidth may be performed by the second PON port instead of the first PON port. There may be a possibility, that the allocation of bandwidth to the first subscriber may be performed by the first PON port and the second PORT. For example, if the first subscriber requires an additional 3 times bandwidth than regular requirements, there may be a possibility that 2x bandwidth is allocated by the first PON port and 1x bandwidth is allocated by the second PON port, if the bandwidth is available at the respective PON ports. Similarly, more than 2 PON ports may be used concurrently by the first subscriber if the required bandwidth is not available at the first and second PON port. This may mean, that the plurality of PON ports may dynamically provision allocation of bandwidth to the first subscriber based on the bandwidth requirement by the first subscriber and the available bandwidth at the plurality of PON ports.
[0051] Similarly, there may be a possibility that while allocating bandwidth to the first subscriber by the plurality of PON ports, only a portion of available bandwidth from the plurality of PON ports is allocated. For example, if the first subscriber requires 3x bandwidth and there may be 3 available PON ports having 4x available bandwidth at each of the plurality of PON ports, then each of the plurality of PON ports may allocate 1x bandwidth (only a portion of total available bandwidth) to the first subscriber, thereby fulfilling the bandwidth requirement. This may be done by the SDN controller 112 to manage the bandwidth allocation of available bandwidth in each of the plurality of PON ports efficiently. This may further be performed by the SDN controller 112 in order to utilize specific PON ports at the OLT 116 for fulfilling the requirement. This may be performed by the SDN controller 112 based on quality or frequency of bandwidth, at the plurality of PON ports, required by the first subscriber.
[0052] The first subscriber may dynamically request a bandwidth in a particular frequency band. This request may be processed by the SDN controller 112, which is further followed by allocation of bandwidth by the plurality of PON ports by increasing, decreasing or modifying the allocated bandwidth quality.
[0053] Further, the dynamic bandwidth management system 120 or the SDN controller 112 switches the first subscriber from the first PON port to the second PON port at the optical line terminal (OLT) 116 through tuning of wavelength of upstream carrier and adjusting bandwidth of wavelength selective optical switch. Typically, the request to adjust bandwidth corresponds to adjustment of the upstream carrier wavelength. The switching occurs when the first bandwidth availability at the first PON port is less than the predefined bandwidth and the second bandwidth availability at the second PON port is more than the predefined bandwidth, where the predefined bandwidth is a required bandwidth by the first subscriber.
[0054] That is, the first subscriber may be at least one of the subscribers in the subscriber group 102, which may be switched to the second PON port upon lack of bandwidth availability at the first PON port. Here, the plurality of PON ports may be used dynamically by a single subscriber group. For example, if the subscriber group having 100 subscribers may be connected to the first PON port and due to sudden bandwidth requirement by the subscriber group, which may not be fulfilled by the first PON port, a few of the subscribers from the subscriber group are switched to another PON port dynamically for fulfilling the bandwidth requirement. This may be achieved by checking the count of subscribers that may be catered by the first PON port, as per its bandwidth availability, and switching the remaining subscriber to the second PON port, which has sufficient available bandwidth to cater to the bandwidth requirements of the remaining subscribers. Similarly, if the bandwidth requirement by the remaining subscribers is not fulfilled by the second PON port, due to high bandwidth requirement, then a third PON port may be utilized in a similar way, for switching second remaining subscribers to the third PON port, having sufficient available bandwidth to fulfil the bandwidth requirements of the second remaining subscribers, the second remaining subscribers may be the count of subscribers in the subscriber group which may not be catered by the first and second PON ports due to lack of available bandwidth.
[0055] Further, the switching of the first subscriber from the first PON port to the second PON at the OLT 116 is performed by dynamically tuning or changing the upstream carrier wavelength of the first subscriber from a first wavelength to a second wavelength. The second wavelength may be decided corresponding to the second PON port, to which the switching of the first subscriber may be performed. Similarly, once the upstream carrier wavelength for the first subscriber is changed from the first wavelength to the second wavelength, an output port of the WSS 114 may be required to be changed corresponding to the second wavelength. The WSS 114 may be connected to the ONU 104 of the first subscriber via a passive optical network layer and to the OLT. The changing of the WSS output port wavelength corresponding to the second wavelength may allow the first subscriber to be moved or tuned to the second PON port, thereby dynamically switching the first subscriber from the first PON port (corresponding to the first wavelength) to the second PON port (corresponding to the second wavelength).
[0056] Conclusively, switching the first subscribers associated with the first PON port on the optical line terminal to another available PON port i.e., the second PON port based on the determination includes tuning the wavelength of upstream carrier of the first subscriber to another wavelength, wherein the another wavelength is associated with the second PON port and logically grouped with a current PON port, adjusting a filter wavelength of the output port of the wavelength selective switch based on the tuned wavelength at the OLT and switching the first subscriber associated with the first PON port on the optical line terminal to the second PON port in response to adjusting the filter wavelength of the output port of the wavelength selective switch.
[0057] The tunable optical transceiver 106 is proposed for the optical network unit 104. The tunable optical transceiver 106 is programmable by the SDN controller 112 via the optical line terminal 116 through an ONU Management Control Interface of the dynamic bandwidth management system. The tunable optical transceiver 106 may tune upstream optical carrier to wavelength in a range of 1290 nanometre to 1330 nanometre. Alternatively, the tunable optical transceiver 106 may tune upstream optical carrier to wavelength in a range of 1260 nanometre to 1280 nanometre. In general, the tunable optical transceivers are fixed transceivers with capability to set channel of emitting laser. In addition, the tunable optical transceivers reduce need to have multiple devices that each operate at fixed wavelengths installed within network. Further, the tunable optical transceivers are available in a DWDM (Dense Wavelength Division Multiplexer) channel spacing or sub-DWDM channel spacing. Furthermore, the tunable optical transceivers are designed for O (Original) Band. Moreover, the tunable optical transceivers support more than or equal to 88 channels that are set with 0.4 nanometre interval.
[0058] That is, the tunable optical transceiver 106 (106a-106b) at the optical network unit 104 which is programmable by the SDN controller 112 via the OLT 116 through the ONU management control interface (OMCI) (not shown) and can tune their upstream optical carrier to any wavelength within the upstream wavelength band (i.e., 1290nm-1330nm and 1270nm-1280nm for GPON and XGSPON, respectively) as prescribed by the ITU-T specification (G.984 and G.988). The OMCI is a protocol for information exchange between the OLT 116 and the ONT defined in the GPON standard. The OMCI supports the configuration management, a fault management, a performance management, and security management. Further, the wavelength selective switch 114 at the central office 100 which functions like a programmable wavelength router and can dynamically tune its output filter bandwidth (0.4/0.8 nm) to allow/block upstream carrier(s) of the ONU 104.
[0059] The interactive computing environment 100 includes the optical power splitter 108. In general, the optic power splitter 108 is based on a quartz substrate of integrated waveguide optical power distribution device. In addition, the optic power splitter 108 is one of the most important passive devices in the optical fibre link. Further, the optic power splitter 108 is an optical fibre tandem device with many input and output terminals, especially applicable to passive optical network (e.g., EPON, GPON, BPON, FTTX, FTTH, and the like). In an aspect of the present disclosure, the optical power splitter 108 includes but may not be limited to Fused Bi-conical Taper (FBT) splitter and Planar Light-wave Circuit (PLC) splitters. In general, Fused Bi-conical Taper is widely accepted and used in passive networks, especially for instances to achieve small split configuration such as 1x2, 1X4, 2x2, and the like. In general, Planar Light-wave Circuit splitters have waveguides fabricated using lithography onto a silica glass substrate that allows to route specific percentages of light.
[0060] The interactive computing environment 100 includes the central office 110. In general, the central office 110 is a point of origination of passive optical network. In addition, the optical fibre is supplied to home or premises of a subscriber from the central office 110. Further, the central office 110 hosts the optical line terminals 116 and optical distribution frames (ODFs). Furthermore, the central office 110 provides necessary powering and includes some important components of a core network. In an aspect of the present disclosure, the central office 110 is initial point of origination of the passive optical network. In addition, the central office 110 includes the SDN controller 112, the wavelength selective switch 114, and the optical line terminal 116. In an aspect of the present disclosure, the central office 110 may include the fabric switch 118.
[0061] In general, the SDN controller 112 in a software-defined networking (SDN) architecture manages flow control for dynamic bandwidth management and application performance. In addition, the SDN controller 112 typically runs on a server and uses protocols to enable switches to send control layer packets. Further, the SDN controller 112 directs traffic according to forwarding policies that a network operator puts in place, thereby minimizing manual configurations for individual network devices. Furthermore, the SDN controller 112 serves as a sort of operating system (OS) for the network. In an aspect of the present disclosure, the dynamic bandwidth management system 120 includes the software-defined networking controller 112, the wavelength selective switch 114, the optical network unit 104, and the optical line terminal 116. In addition, the wavelength selective switch 114 is connected to the optical line terminal 116 and the SDN controller 112 for data plane and control plane connectivity, respectively. In another aspect of the present disclosure, the dynamic bandwidth management system 120 is placed outside the software-defined networking controller 112.
[0062] In general, the optical line terminal 116 is equipment integrating L2/L3 switch function in the passive optical network. In addition, the optical line terminal 116 contains a plurality of equipment. Further, the plurality of equipment includes rack, CSM (Control and Switch Module), ELM (EPON Link Module, PON card), redundancy protection -48V DC power supply modules or one 110/220V AC power supply module, and fans. Furthermore, the optical line terminal 116 is used to control information float across Optical Distribution Network (ODN), going both directions. Moreover, the optical line terminal 116 is located in the central office 110. In an aspect of the present disclosure, the optical line terminal 116 has two float directions. The two float directions include upstream and downstream.
[0063] In an aspect of the present disclosure, the wavelength selective switch 114 dynamically routes, blocks and attenuates DWDM (Dense Wavelength Division Multiplexer) or sub-DWDM wavelengths within the passive optical network. The wavelength selective switch 114 is a programmable wavelength router. The wavelength selective switch 114 blocks or un-blocks a wavelength carrier at the output port. In addition, the wavelength selective switch 114 tunes output filter bandwidth to allow upstream carrier of the optical network unit 104. In addition, the SDN controller 112 controls configuration of the wavelength selective switch 114. Further, the optical network unit 104 is connected with the optical line terminal 116 through the wavelength selective switch 114. Furthermore, the wavelength selective switch 114 comprises an array of wavelength selective switches to form and support different configurations. In an aspect of the present disclosure, the SDN controller 112 groups the plurality of PON ports available at the optical line terminal 116. In addition, the SDN controller 112 allows the subscriber group 102 to switch on the plurality of PON ports to achieve required wavelength and bandwidth. Further, the plurality of PON ports include but may not be limited to broadband passive optical network (BPON), Ethernet passive optical network (EPON or GEPON) port, gigabit passive optical network (GPON or XGPON or XGSPON) port, and any other next-generation broadband PON technologies, (NGPON2). The Ethernet passive optical network (EPON or GEPON) port uses the Institute of Electrical and Electronics Engineers (IEEE) standards 802.3.
[0064] The interactive computing environment 100 includes the fabric switch 118. In general, the fabric switch 118 is a two layer network topology composed of leaf switches and spine switches. In general, servers and storage connect with leaf switches. In addition, the leaf switches connect with the spine switches. Further, the leaf switches aggregate traffic from server nodes and connects to core of network. Furthermore, the leaf switches mesh into the spine switches, forming access layer that delivers network connection points for servers. The fabric switch 118 may reside inside or outside the Central Office, depending upon the network operator deployment scenario.
[0065] The dynamic bandwidth management system 120 determines start time and length of transmission time slot for the optical line terminal 116. In addition, the dynamic bandwidth management system 120 calculates bandwidth demand for logical queue at the optical line terminal 116 associated with specific quality of service (QoS) based on traffic and bandwidth information. Further, the dynamic bandwidth management system 120 schedules upstream traffic through construction of upstream bandwidth maps.
[0066] Advantageously, the dynamic bandwidth allocation (DBA) may be required to efficiently utilize limited resources (herein, PON ports) of network devices (herein, OLT) and cater the need of sudden change in the bandwidth requirements by users/subscribers. Without dynamic bandwidth allocation, the bandwidth requirements of subscribers may be fulfilled by the hard wired or pre-mapped PON port, which leads to an inefficient resource utilization. Such kind of system, which does not use the DBA method, may not be able to cater the requirements of subscribers if the subscribers require additional bandwidth than the available bandwidth in the mapped PON port. Similarly, if the subscriber require very less bandwidth, then the pre-mapped PON port may not be completely utilized, leading to an inefficient resource utilization. With DBA and the present disclosure, the interactive computing environment may be able to combine partial or complete multiple PON ports of an OLT in order to cater the dynamic bandwidth requirements of the subscriber (or groups).
[0067] For a high bandwidth requirement service, such as AR or VR, the plurality of PON ports at the OLT may be able to combine partially or completely, in order to cater the high bandwidth requirements of the service. Similarly, for a low bandwidth requirement service, such as text messaging or email, a remaining available bandwidth at the connected PON port may be utilized by other services in the system.
[0068] FIGS. 4-7 are example illustrations of various PON architectures 500-800 in which dynamic bandwidth allocation is explained. Various functions and operations of the subscriber group 102, the optical network unit 104, the tunable optical transceiver 106, the optic power splitter 108, the central office 110, the SDN controller 112, the wavelength selective switch 114, the optical line terminal 116, the fabric switch 118, and the dynamic bandwidth management system 120 are explained in connection/conjunction with the FIG. 3.
[0069] The central office 110 may include an Open Network Operating System (ONOS). The ONOS may support the SDN controller 112 for building next-generation SDN/ Network function virtualization (NFV) solutions. In addition, the ONOS act as a platform and includes a set of applications that act as an extensible, modular, distributed SDN controller. The ONOS may enable a simplified management, configuration and deployment of new software, hardware and services in the SDN controller 112. The ONOS also supports both configuration and real-time control of the network, eliminating the need to run routing and switching control protocols inside a network fabric in the PONS. By moving intelligence into the ONOS, the various techniques may be enabled and end-users may easily create new network applications without the need to alter a dataplane system.
[0070] The central office 110 may also include a vOLTHA. The vOLTHA may stand for a virtual OLT hardware abstraction component that supports the CORD Project objective of multi-vendor, multi-domain "any broadband access as a service" reference implementation for the Central Office 110. The VOLTHA may provide isolation between an abstract (vendor agnostic) PON management system, and a set of vendor-specific and white-box PON hardware devices.
[0071] The central office 110 may also include a service orchestrator. The service orchestrator arranges, sequences, and implements tasks based on rules and policies to coordinate the creation, modification, or removal of logical and physical resources in a service environment. The service orchestrator provides orchestration at a very high level, with an end-to-end view of the infrastructure, network, and applications.
[0072] As shown in the FIG. 5, with programmable optical PON, the subscriber can seamlessly switch from the GPON to the XGS-PON or the NG-PON to the NG-PON2 subscription. As shown in the FIG. 6 and FIG. 7, with the programmable PON, grouping of two or more physical PON ports into one single logical PON port of higher capacity is achieved. The type-B protection of the PON ports provides a backup protection against the failure of optical transceivers.
[0073] FIG. 8 illustrates a flowchart 900 of a method for enabling dynamic bandwidth control in passive optical network over the FTTx network infrastructure. It may be noted that in order to explain the method steps of the flowchart 900, references will be made to the elements explained in FIGs. 3-7. The steps 902-912 are performed by the dynamic bandwidth management system (120).
[0074] At 902, the method includes receiving the request to adjust the bandwidth from at least one subscriber among the subscriber group 102. The request to adjust the bandwidth includes increasing (scaling up) or decreasing (scaling down) the bandwidth requirements from at least one subscriber among the subscriber group 102. At 904, the method includes sending the request to the SDN controller 112 to adjust a bandwidth profile of the at least one subscriber among the plurality of groups 102. At 906, the method includes determining the bandwidth usage of each of the PON port 122a-122c at an optical line terminal 116 and a QoS of other subscribers among the plurality of groups 102. At 908, the method includes tuning a wavelength of upstream carrier of the subscriber to another wavelength. Another wavelength is associated with the available PON port and logically grouped with a current PON port. At 910, the method includes adjusting the filter wavelength of an output port of a wavelength selective switch based on the tuned wavelength at the OLT. At 912, the method includes switching other subscribers associated with the at least one PON port on the optical line terminal 116 to another available PON port in response to adjusting the filter wavelength of the output port of the wavelength selective switch 114. That is, switching the first subscriber from the first PON port to the second PON port at the optical line terminal (OLT), when the first bandwidth availability at the first PON port is less than a predefined bandwidth and the second bandwidth availability at the second PON port is more than the predefined bandwidth, wherein the predefined bandwidth is a required bandwidth by the first subscriber.
[0075] It may be noted that the flowchart 900 is explained to have above stated process steps; however, those skilled in the art would appreciate that the flowchart 900 may have more/less number of process steps which may enable all the above stated embodiments of the present disclosure.
[0076] FIG. 9 illustrates the block diagram of a computing device 1000. The computing device 1000 includes a bus 1002 that directly or indirectly couples the following devices: memory 1004, one or more processors 1006, one or more presentation components 1008, one or more input/output (I/O) ports 1010, one or more input/output components 1012, and a power supply 1014. The bus 1002 represents what may be one or more busses (such as an address bus, data bus, or combination thereof). Although the various blocks of FIG. 9 are shown with lines for the sake of clarity, in reality, delineating various components is not so clear, and metaphorically, the lines would more accurately be grey and fuzzy. For example, one may consider a presentation component such as a display device to be an I/O component. Also, the processors 1006 have the memory 1004. The inventors recognize that such is the nature of the art, and reiterate that the diagram of FIG. 9 is merely illustrative of an exemplary computing device 1000 that can be used in connection with one or more embodiments of the present invention. Distinction is not made between such categories as “workstation,” “server,” “laptop,” “hand-held device,” etc., as all are contemplated within the scope of FIG. 9 and reference to “computing device.”
[0077] The computing device 1000 typically includes a variety of computer-readable media. The computer-readable media can be any available media that can be accessed by the computing device 1000 and includes both volatile and non-volatile media, removable and non-removable media. By way of example, and not limitation, the computer-readable media may comprise computer storage media and communication media. The computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information such as computer-readable instructions, data structures, program modules or other data.
[0078] The computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by the computing device 1000. The communication media typically embodies computer-readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media. Combinations of any of the above should also be included within the scope of computer-readable media.
[0079] Memory 1004 includes computer-storage media in the form of volatile and/or non-volatile memory. The memory 1004 may be removable, non-removable, or a combination thereof. Exemplary hardware devices include solid-state memory, hard drives, optical-disc drives, etc. The computing device 1000 includes one or more processors that read data from various entities such as memory 1004 or I/O components 1012. The one or more presentation components 308 present data indications to a user or other device. Exemplary presentation components include a display device, speaker, printing component, vibrating component, etc. The one or more I/O ports 1010 allow the computing device 1000 to be logically coupled to other devices including the one or more I/O components 1012, some of which may be built in. Illustrative components include a microphone, joystick, game pad, satellite dish, scanner, printer, wireless device, etc.
[0080] The foregoing descriptions of specified embodiments of the present technology have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present technology to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present technology and its practical application, to thereby enable others skilled in the art to best utilize the present technology and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present technology.
[0081] While several possible embodiments of the disclosure have been described above and illustrated in some cases, it should be interpreted and understood as to have been presented only by way of illustration and example, but not by limitation. Thus, the breadth and scope of a preferred embodiment should not be limited by any of the above-described exemplary embodiments.
[0082] It will be apparent to those skilled in the art that other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention. While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The invention should therefore not be limited by the above described embodiment, method, and examples, but by all embodiments and methods within the scope of the invention. It is intended that the specification and examples be considered as exemplary, with the true scope of the invention being indicated by the claims.
[0083] The methods and processes described herein may have fewer or additional steps or states and the steps or states may be performed in a different order. Not all steps or states need to be reached. The methods and processes described herein may be embodied in, and fully or partially automated via, software code modules executed by one or more general purpose computers. The code modules may be stored in any type of computer-readable medium or other computer storage device. Some or all of the methods may alternatively be embodied in whole or in part in specialized computer hardware.
[0084] The results of the disclosed methods may be stored in any type of computer data repository, such as relational databases and flat file systems that use volatile and/or non-volatile memory (e.g., magnetic disk storage, optical storage, EEPROM and/or solid state RAM).
[0085] The various illustrative logical blocks, modules, routines, and algorithm steps described in connection with the embodiments disclosed herein can be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. The described functionality can be implemented in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the disclosure.
[0086] Moreover, the various illustrative logical blocks and modules described in connection with the embodiments disclosed herein can be implemented or performed by a machine, such as a general purpose processor device, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components or any combination thereof designed to perform the functions described herein. A general purpose processor device can be a microprocessor, but in the alternative, the processor device can be a controller, microcontroller, or state machine, combinations of the same, or the like. A processor device can include electrical circuitry configured to process computer-executable instructions. In another embodiment, a processor device includes an FPGA or other programmable device that performs logic operations without processing computer-executable instructions. A processor device can also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. Although described herein primarily with respect to digital technology, a processor device may also include primarily analog components. A computing environment can include any type of computer system, including, but not limited to, a computer system based on a microprocessor, a mainframe computer, a digital signal processor, a portable computing device, a device controller, or a computational engine within an appliance, to name a few.
[0087] Conditional language used herein, such as, among others, "can," "may," "might," "may," “e.g.,” and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or steps. Thus, such conditional language is not generally intended to imply that features, elements and/or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without other input or prompting, whether these features, elements and/or steps are included or are to be performed in any particular embodiment. The terms “comprising,” “including,” “having,” and the like are synonymous and are used inclusively, in an open-ended fashion, and do not exclude additional elements, features, acts, operations, and so forth. Also, the term “or” is used in its inclusive sense (and not in its exclusive sense) so that when used, for example, to connect a list of elements, the term “or” means one, some, or all of the elements in the list.
[0088] Disjunctive language such as the phrase “at least one of X, Y, Z,” unless specifically stated otherwise, is otherwise understood with the context as used in general to present that an item, term, etc., may be either X, Y, or Z, or any combination thereof (e.g., X, Y, and/or Z). Thus, such disjunctive language is not generally intended to, and should not, imply that certain embodiments require at least one of X, at least one of Y, or at least one of Z to each be present.
[0089] While the above detailed description has shown, described, and pointed out novel features as applied to various embodiments, it can be understood that various omissions, substitutions, and changes in the form and details of the devices or algorithms illustrated can be made without departing from the scope of the disclosure. As can be recognized, certain embodiments described herein can be embodied within a form that does not provide all of the features and benefits set forth herein, as some features can be used or practiced separately from others.

We claim:

1.A method of dynamic bandwidth allocation, the method comprising:
switching, by a software-defined network controller (112), a first subscriber from a first passive optical network (PON) port to a second PON port at an optical line terminal (OLT) (116) when a first bandwidth availability at the first PON port is less than a predefined bandwidth and a second bandwidth availability at the second PON port is more than the predefined bandwidth, wherein the predefined bandwidth is a required bandwidth by the first subscriber.

2. The method as claimed in claim 1, further comprising:
receiving a request from the first subscriber for the predefined bandwidth allocation.

3. The method as claimed in claim 1, further comprising:
allocating the predefined bandwidth to the first subscriber, by the second PON port, when the first bandwidth availability at the first PON port is less than the predefined bandwidth, required by the first subscriber.

4. The method as claimed in claim 1, further comprising:
checking a bandwidth availability at a plurality of PON ports associated with the OLT;
selecting a sub-plurality of PON ports where bandwidth availability is more than the predefined bandwidth; and
selecting the second PON port from the sub-plurality of PON ports for switching the first subscriber from the first PON port to the second PON port.

5. The method as claimed in claim 1, further comprising:
allocating the predefined bandwidth to the first subscriber, by the second PON port, when the first bandwidth availability at the first PON port is less than the predefined bandwidth, and a second bandwidth availability at the second PON port is more than the predefined bandwidth,
wherein the allocation of the predefined bandwidth further comprising allocating a portion of the second bandwidth availability to the first subscriber.

6. The method as claimed in claim 1, wherein switching the first subscriber from the first PON port to the second PON port at the optical line terminal (OLT) further comprising:
changing a first wavelength of upstream carrier of the first subscriber to a second wavelength at an optical network unit (ONU) (104) associated with the first subscriber, wherein the second wavelength is associated with the second PON port.

7. The method as claimed in claim 1, wherein switching the first subscriber from the first PON port to the second PON port at the optical line terminal (OLT) further comprising:
changing a first wavelength of upstream carrier of the first subscriber to a second wavelength at an optical network unit (ONU) (104) associated with the first subscriber, wherein the second wavelength is associated with the second PON port;
tuning a filter wavelength of an output port of a wavelength selective switch (114) catering to the OLT, in accordance to the changed first wavelength of upstream carrier of the first subscriber, at the ONU; and
switching the first subscriber associated with the first PON port to the second PON port, in response to tuning the filter wavelength of the output port of the wavelength selective switch (114).

8. A system (100) of dynamic bandwidth allocation, the system (100) comprises a subscriber group (102), an optical network unit (ONU) (104), a software-defined network (SDN) controller (112) and an optical line terminal (OLT) (116), the SDN controller (112) configured to:
switch a first subscriber of the subscriber group (102) from a first passive optical network (PON) port to a second PON port at the OLT (116) when a first bandwidth availability at the first PON port is less than a predefined bandwidth and a second bandwidth availability at the second PON port is more than the predefined bandwidth, wherein the predefined bandwidth is a required bandwidth by the first subscriber.

9. The system (100) as claimed in claim 8 receives a request from the first subscriber for the predefined bandwidth allocation.

10. The system (100) as claimed in claim 8 allocates the predefined bandwidth to the first subscriber, by the second PON port, when the first bandwidth availability at the first PON port is less than the predefined bandwidth, required by the first subscriber.

11. The system (100) as claimed in claim 8 is configured to:
check a bandwidth availability at a plurality of PON ports associated with the OLT (116);
select a sub-plurality of PON ports where bandwidth availability is more than the predefined bandwidth; and
select the second PON port from the sub-plurality of PON ports for switching the first subscriber from the first PON port to the second PON port.

12. The system (100) as claimed in claim 8, allocates the predefined bandwidth to the first subscriber, by the second PON port, when the first bandwidth availability at the first PON port is less than the predefined bandwidth, and a second bandwidth availability at the second PON port is more than the predefined bandwidth, wherein the allocation of the predefined bandwidth further comprising allocating a portion of the second bandwidth availability to the first subscriber.

13. The system (100) as claimed in claim 8, wherein switch the first subscriber from the first PON port to the second PON port at the OLT (116) comprises changing a first wavelength of upstream carrier of the first subscriber to a second wavelength at the ONU (104) associated with the first subscriber, wherein the second wavelength is associated with the second PON port.

14. The system (100) as claimed in claim 8, wherein switch the first subscriber from the first PON port to the second PON port at the OLT (116) comprises:
change a first wavelength of upstream carrier of the first subscriber to a second wavelength at the ONU (104) associated with the first subscriber, wherein the second wavelength is associated with the second PON port;
tune a filter wavelength of an output port of a wavelength selective switch (114) catering to the OLT, in accordance to the changed first wavelength of upstream carrier of the first subscriber, at the ONU; and
switch the first subscriber associated with the first PON port to the second PON port, in response to tuning the filter wavelength of the output port of the wavelength selective switch (114).