The present subject matter relates to wireless communication networks and,
particularly, but not exclusively, to Long Term Evolution (LTE) communication networks.
[0002] Wireless communication networks are deployed for various types of data content,
such as voice, data, audio, and video. Wireless communication networks have evolved a long way
from 1" generation in which voice was transmitted as analog signals in a circuit switched network
to 4th Generation wireless networks in which voice and data are transmitted as digital signals in a
packet switched network. 4th Generation wireless networks are also referred to as Long Term
Evolution (LTE) and offer a variety of services including HDTV, gaming, 3D television, etc.
[0003] LTE communication networks are deployed by telecom service providers who offer
a variety of services to their subscribers. Telecom service providers offer wireless communication
services to subscribers who use User Equipment (UE) to avail of the services of their telecom
service provider. The UE used by subscribers may include laptop computers, mobile devices,
portable digital assistants, GPS devices, etc.
[0004] LTE, the 4th generation standard for wireless communication is defined by the 3rd
Generation Partnership Project (3GPP). 3GPP is a collaboration between groups of telecom
associations. 3GPP was initially formed to make a globally applicable 3rd generation mobile phone
system specification, and scope of 3GPP has evolved from there to also describe standardization of
4th Generation LTE communication networks.
[OOOS] This summary is provided to introduce concepts related to providing connectivity to
subscribers of telecom service providers in a wireless communication network. This summary is
not intended to identify essential features of the claimed subject matter nor is it intended for use in
determining or limiting the scope of the claimed subject matter.
[0006] In one implementation, a method to provide connectivity to User Equipments (UEs)
utilized by subscribers of telecom service providers in a Long Term Evolution (LTE)
communication network, is described. The method includes identifying a list of Public Land
Mobile Network (PLMNs), where each PLMN is associated to a telecom service provider, and the
list of PLMNs includes at least one primary PLMN. In the said implementation, the connectivity
status of the at least the primary PLMN is determined, where a connectivity status of the PLMN is
indicative of whether the PLMN provides a user plane connectivity to the UE. The connectivity
status is further encoded into a "Modified SIB Typel" message.
[0007] In one implementation, a method for connecting to a LTE communication network
is described. The method includes receiving a "Modified SIB Typel" message, where the
"Modified SIB Typel" message includes a list of Public Land Mobile Networks (PLMNs), where
the list of PLMNs share a base station and the list of PLMNs include at least a primary PLMN. In
the said implementation, the connectivity status of at least one PLMN from the list of PLMNs is
decoded, where the connectivity status is indicative of whether the at least one PLMN provides
user plane connectivity to the UE. Based on the connectivity status, the UE may determine
whether to camp on the base station, that is shared by the list of PLMNs.
[OOOS] In one implementation, a base station for providing connectivity to UEs utilized by
subscribers of telecom service providers in a LTE communication network is described. The base
station includes a processor. The base station further comprises a connectivity determination
module coupled to the processor, which identifies a list of Public Land Mobile Networks (PLMNs)
that are associated with the telecom service providers, and where the list of PLMNs include a
primary PLMN. The connectivity determination module further determines a connectivity status of
the at least the primary PLMN, where the connectivity status is indicative of whether the at least
primary PLMN provides user plane connectivity to the UE. The base station further comprises an
encoding module which encodes the connectivity status of the at least the primary PLMN into a
"Modified SIB Typel" message, where the "Modified SIB Typel" message includes information
relevant for the UE to camp on the base station.
[0009] In another implementation, a UE for receiving connectivity in a LTE
communication network, the UE includes a processor, a receiving module coupled to the
processor. The receiving module receives a "Modified SIB Typel" message, where the "Modified
SIB Typel" message includes a list of Public Land Mobile Network (PLMNs) that share a base
station and, where the list of PLMNs includes at least a primary PLMN. The decoding module also
decodes a connectivity status of the at least the primary PLMN, where the connectivity status is
indicative of whether the at least the primary PLMN provides user plane connectivity to the UE.
[OOlO] In an implementation, a non-transitory computer readable medium having a set of
computer readable instructions is described that, when executed, causes a computing system to
identify a list of Public Land Mobile Networks (PLMNs) sharing a base station, where the plurality
of PLMNs is associated with the telecom service providers, and where the list of PLMNs includes
a primary PLMN. In the said implementation, a connectivity status associated with at least the
primary PLMN is determined, where the connectivity status is indicative whether the at least the
primary PLMN provides user plane functions to the subscribers. The computing system further
encodes the connectivity status determined for the at least the primary PLMN into a "Modified
SIB Typel" message, where the "Modified SIB Typel" message comprises information relevant
for the UEs to camp on the base station.
BRIEFD ESCRIPTIOONF THE FIGURES
[OOll] The detailed description is described with reference to the accompanying figures. In
the figures, the left-most digit(s) of a reference number identifies the figure in which the reference
number first appears. The same numbers are used throughout the figures to reference like features
and components. Some embodiments of system andor methods in accordance with embodiments
of the present subject matter are now described, by way of example only, and with reference to the
accompanying figures, in which:
[0012] Fig. 1 illustrates an exemplary LTE communication network environment,
according to an embodiment of the present subject matter;
[0013] Fig. 2 schematically illustrates network entities providing connectivity to Users
Equipments (UEs) of subscribers in an LTE communication network, in accordance with an
embodiment of the present subject matter;
[0014] Fig. 3(a) illustrates a method of providing connectivity to UEs of the subscribers in
the LTE communication network, in accordance with an embodiment of the present subject matter;
and
[OOlS] Fig. 3(b) illustrates another method of providing connectivity to UEs of the
subscribers in the LTE communication network, in accordance with an embodiment of the present
subject matter.
[0016] It should be appreciated by those skilled in the art that any block diagram herein,
represent conceptual views of illustrative systems embodying the principles of the present subject
matter. Similarly, it will be appreciated that any flow charts, flow diagrams, and the like represent
various processes which may be substantially represented in computer readable medium and so
executed by a computer or processor, whether or not such computer or processor is explicitly
shown.
[0017] In the present document, the word "exemplary" is used herein to mean "serving as
an example, instance, or illustration." Any embodiment or implementation of the present subject
matter described herein as "exemplary" is not necessarily to be construed as preferred or
advantageous over other embodiments.
[0018] Systems and methods for providing connectivity to subscribers of telecom service
providers in a wireless communication network are described, in accordance with an
implementation of the present subject matter. The methods can be implemented in various
communication devices communicating through various networks. Although the description herein
is provided largely with reference to Long Term Evolution (LTE) wireless networks, the methods
and systems may be implemented in other networks providing data connectivity, albeit with a few
variations, as will be understood by a person skilled in the art.
[0019] The techniques described herein may be used for various wireless communication
systems, such as Code Division Multiple Access (CDMA), Time Division Multiple Access
(TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency-Division Multiple
Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA) and other
systems. A CDMA system may implement a radio technology, such as Universal Terrestrial Radio
Access (UTRA), cdma2000, etc. UTRA includes variants of CDMA. cdma2000 covers IS-2000,
IS-95 and IS-856 standards. A TDMA system may implement a radio technology, such as Global
System for Mobile Communications (GSM). An OFDMA system may implement a radio
technology, such as Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.20,
IEEE 802.16 (WiMAX), 802.1 1 ( ~ i ~ i la~sh-~OF)DM, @ ~ etc. UTRA and E-UTRA are part of
Universal Mobile Telecommunication System (UMTS). 3GPP Long Term Evolution (LTE) is an
upcoming release of UMTS that uses E-UTRA. UTRA, E-UTRA, UMTS, LTE and GSM are
described in documents from an organization "3rd Generation Partnership Project" (3GPP).
cdma2000 and UMB are described in documents from an organization named "3rd Generation
Partnership Project 2" (3GPP2). For clarity, certain aspects of the techniques are described below
for LTE, and 3GPP terminology is used in much of the description below.
[0020] LTE communication networks are largely divided into core network and radio
access network. The core network includes a Mobility Management Entity (MME) which provides
control plane functions related to subscriber and session management. The core network also
includes a Serving Gateway (S-GW) which provides user plane connectivity, and forwards packets
to and from the radio access network. The core networks are also referred to as Evolved Packet
core (EPC), which comprises of one or more Public Land Mobile Networks (PLMNs). Each
PLMN is operated by a telecom service provider to provide differentiated services to their
subscribers. The core network in the LTE communication network is generally a packet switched
core architecture.
[0021] Further, the functionalities of the LTE communication networks can be broadly
divided into two planes, a control plane and a user plane. The control plane functions include
network mapping, which essentially identifies a routing map for data traffic. The user plane
functions include routing of the data traffic for LTE communication network management.
[0022] The radio access network of the LTE communication network, or an Evolved
UMTS Terrestrial Radio Access Network (E-UTRAN), provides a radio interface between
subscriber's User Equipment (UE) and the PLMN of the telecom service provider. A radio base
station of the E-UTRAN providing radio access to the subscribers, is called Evolved NodeB (eNB)
or Home Evolved NodeB (HeNB). For the sake of explanation, the eNB or the HeNB is referred
to, in the description hereinafter, as a 'cell' or a 'base station'.
[0023] In some cases, telecom service providers share network elements of a LTE
communication network, allowing the telecom service providers to share the investment of capital
expenditure in establishing and operating the wireless LTE communication networks. 3GPP
specification describes architectures in which different telecom service providers can share
elements of the wireless LTE communication networks. 3GPP specification includes two types of
architecture for sharing, Gateway Core Network (GWCN) and Multi-Operator Core Network
(MOCN). In GWCN, MME of the core network and a base station of the E-UTRAN may be
shared, while in MOCN architecture, only the base station is shared.
[0024] As described above, a base station is shared amongst several telecom service
providers in both GWCN and MOCN architectures. Telecom services are provided by telecom
service providers to their UE utilizing subscribers through the shared base station. Each telecom
service provider is associated to a PLMN to provide differentiated services to their subscribers.
The subscriber can utilize the differentiated services provided by the telecom service providers
when the UE utilized by them selects one of such base station of the wireless LTE communication
network to receive a radio interface to the PLMN of the telecom service provider. The process of
selecting a base station is also referred to as 'camping to a base station', as would be appreciated
by those skilled in the art.
[0025] The process by which a UE selects a base station to camp on a base station is
referred to as base station selection or reselection. Generally, the base station broadcasts
information about each of the telecom service providers that share the base station, and the
broadcasted information is received by an UE in the receivable range of the base station. The UE
uses the received information to decide on the most optimal base station to camp on, in order to
connect to the PLMN of the telecom service provider. Once the UE camps on a base station, it can
avail telecom services provided by the telecom service provider, such as, making a phone call or
posting information on the internet. Further, in situations where UE determines that the telecom
service provider associated with the UE does not provide connectivity, the UE may identify other
base station and may initiate camping procedure.
[0026] The structure of information that is broadcasted by the base station is standardized
by a 3GPP specification. 3GPP specifies a System Information Block (SIB) data structure to
broadcast information about the telecom service providers sharing the base station. The SIB
message includes information, but not limited to, PLMN Identity List, Radio and network
capabilities, etc. which can be used by the UE to identify an appropriate base station to camp on.
The PLMN identity list includes unique identities of all the PLMNs, including a primary PLMN,
associated with different telecom service providers that share the base station. In the PLMN
identity list, the primary PLMN is listed as the first PLMN while other secondary PLMNs are
listed thereafter in the PLMN identity list. Primary PLMN may be used to construct several
identifiers including Evolved Global Cell Identifier (EGCI). The EGCI is constructed from the
primary PLMN identity and the Cell Identity (CI).
[0027] A PLMN may be considered unavailable in scenarios like when an interface with
the base station goes down. The interface with the base station may include, interface with the
MME and interface with the S-GW. The PLMN and base station may not have connectivity if the
base station has stopped receiving responses from the core network, or when user plane
connectivity is unavailable.
[OOZS] Conventionally, when the primary PLMN of a telecom service provider sharing the
base station and providing connectivity to its subscribers becomes unavailable, correspondingly
the entire base station, sharing multiple telecom service providers, also becomes unavailable. In
other words, at instances when the primary PLMN is unable to provide connectivity to the
subscribers of the telecom service provider associated with the primary PLMN, the base station
being shared among multiple telecom service providers is closed and made unavailable to all the
UEs. Since the base station is unavailable for all the UEs to camp on, the secondary PLMNs of
other telecom service providers sharing the base station are also not reachable through the base
station. In such a scenario, even though only the primary PLMN is unavailable, subscribers of the
secondary PLMNs also cannot camp on the base station and have to reconnect to another base
station. Therefore, the UEs of the secondary PLMN cannot use telecom services of the secondary
PLMN through that base station and are forced to camp on another available base station.
[0029] For example, if telecom service providers A and B share a base station B1, where
the telecom service provider A is associated with the primary PLMN and the telecom service
provider B is associated with the secondary PLMN. If telecom service provider A becomes
unavailable, then the base station becomes unavailable for UEs to camp on. In this scenario, even
subscribers of the telecom service provider B are forced to camp on to another base station.
Therefore, in case of primary PLMN becoming unavailable, the subscribers of the secondary
PLMN are inconvenienced by the type of functioning of the base station.
[0030] According to an implementation of the present subject matter, systems and methods
for providing connectivity to subscribers of telecom service providers in a wireless communication
network are described, in accordance with an implementation of the present subject matter. In said
implementation, the base station is configured to transmit a 'modified SIB typel ' message. In said
implementation, the 'modified SIB typel' message may include a connectivity status
corresponding to each of the PLMNs sharing the base station. Further, the 'modified SIB typel'
message may also include other parameters included in a typical 'SIB typel' message. The base
station may transmit the 'modified SIB typel' with information including the list of PLMNs
identities, where each PLMN identity is associated with the connectivity status of the telecom
service provider. In one implementation, the connectivity status can be a flag to indicate whether
the associated PLMN is either available or unavailable. In said implementation, the availability
may be denoted by a parameter plmnAvailable and the PLMN unavailability may be denoted by a
parameter plmnunavailable.
[0031] In another implementation, the connectivity status of only the primary PLMN may
be associated with the modified SIB typel. The connectivity status corresponding to each of the
PLMN may indicate whether the telecom service provider is available or not for connection of the
UE through the particular base station to provide telecom services. Further, in said
implementation, the modified SIB typel may be transmitted by the base station in a similar
manner, as a SIB message is transmitted.
[0032] According to the implementation of the present subject matter, since the
connectivity status of the PLMN is transmitted in the modified SIB typel message, the UEs are
aware of the of availability of PLMN and can select available PLMNs using other information in
the base station for the purposes of selection or reselection to camp on the base station.
[0033] For example, consider that telecom service providers OP 1,OP2, and OP3 share a
base station B2, in which OP1 is associated to the primary PLMN. In such a situation, if the
primary PLMN is unavailable, then base station B2 may transmit a modified SIB typel message
with information of list of PLMN identities along with their corresponding connectivity status. In
said example, the connectivity status may be associated with each PLMN identity individually,
such as (OP 1, plmnunavailable) , (OP2, plmnAvailable) , and f OP3, plrnnAvailable) . Upon
receiving such a modified SIB typel message, subscribers of the telecom service provider OP 1
may determine that the PLMN corresponding to the telecom service provider OP1 is unavailable
and may therefore use information received from other nearby base stations to find another most
suitable base station to camp on.
[0034] Although the description herein is with reference to LTE communication networks,
the systems and the methods may be implemented in other networks and devices that may or may
not be supported by the IMS network, albeit with a few variations, as will be understood by a
person skilled in the art. The other communication networks may include Global System for
Mobile Communication (GSM) network, Universal Mobile Telecommunications System (UMTS)
network, IP Multimedia Subsystem (IMS), Personal Communications Service (PCS) network,
Time Division Multiple Access (TDMA) network, Code Division Multiple Access (CDMA)
network, Next Generation Network (NGN), Public Switched Telephone Network (PSTN), and
Integrated Services Digital Network (ISDN).
[0035] It should be noted that the description merely illustrates the principles of the present
subject matter. It will thus be appreciated that those skilled in the art will be able to devise various
arrangements that, although not explicitly described herein, embody the principles of the present
subject matter and are included within its spirit and scope. Furthermore, all examples recited
herein are principally intended expressly to be only for pedagogical purposes to aid the reader in
understanding the principles of the invention and the concepts contributed by the inventor(s) to
furthering the art, and are to be construed as being without limitation to such specifically recited
examples and conditions. Moreover, all statements herein reciting principles, aspects, and
embodiments of the invention, as well as specific examples thereof, are intended to encompass
equivalents thereof.
[0036] The systems and the methods can be implemented in a variety of entities, such as
communication devices, and computing systems. The entities that can implement the described
method(s) include, but are not limited to, desktop computers, hand-held devices, laptops or other
portable computers, tablet computers, mobile phones, PDAs, Smartphones, and the like. Further,
the method may also be implemented by devices capable of exchanging data to provide
connectivity to different communicating devices and computing systems. Such devices may
include, but are not limited to, Radio Network Controller (RNC), Base Transceiver Station (BTS),
Mobile Switching Centre (MSC), Short Message Service Centre (SMSC), Base Station Subsystem
(BSS), Home Location Register (HLR), Visitor Location Register (VLR), Authentication Center
(AuC), data cards, mobile adapters, wireless ( ~ i ~adaipt~ers,~ rou)ter s, and the like.
[0037] The manner in which the systems and methods are implemented for providing
connectivity to subscribers, in a LTE communication network, has been explained in details with
respect to the Figures 1-3. While aspects of described systems and methods for providing radio
connectivity to a subscriber can be implemented in any number of different computing systems,
transmission environments, and/or configurations, the embodiments are described in the context of
the following exemplary system(s).
[0038] Fig. 1 illustrates a LTE communication environment 100 operated by telecom
service providers to offer telecom services to subscribers of the telecom service provider,
according to an embodiment of the present subject matter. The LTE communication environment
100 comprises infrastructure including Public Land Mobile Networks (PLMNs) 102- 1, 102-2, . . . ,
102-N, commonly referred to as PLMNs 102 and individually referred to as PLMN 102
hereinafter. The LTE communication environment 100 also includes a radio base station 104 for
providing connectivity between the PLMNs 102 and User Equipments (UEs) 106- 1, 106-2, 106-3,
. . . , 106-N. For the sake of explanation, the radio base station is referred to a base station 104
hereinafter and, the UEs 106- 1, 106-2, 106-3, . . . , 106-N are commonly referred to as UEs 106.
The Telecom service providers may provide telecom services to their subscribers through the LTE
communication environment 100 via UEs 106 utilized by the subscribers.
[0039] The communication between the UEs 106 and the base station 104 may be through
a radio access network such as the Evolved Universal Terrestrial Access Network (E-UTRAN). In
one implementation, the UEs 106 may communicate with the base station 104 over the radio
network utilizing the E-UTRAN while the base station 104 communicates with the PLMNs 102
over an IP network. The E-UTRAN and the IP network are not depicted in the figure for the sake
of brevity.
[0040] Subscribers use UEs 106 to use telecom services that are made available by the
telecom service providers associated to the PLMNs 102, through a radio interface enabled by base
station 104. The UEs 106 may include any communication device including, but not limited to,
desktop computers, hand-held devices, laptops or other portable computers, network computers,
mobile phones or any device capable of communication in the LTE communication environment
100.
[0041] It may be understood by a person skilled in the art, that an LTE communication
environment 100 may have several base stations 104 in the network to effectively support
subscribers who may be placed across a geographical region. Further, it may also be understood
that a telecom service provider associated with one PLMN may share one or more base stations
104. A single base station 104 shared by multiple PLMNs 102 has been considered for ease of
description. Further, it would be appreciated that each subscriber associated with a UE, such as the
UE 106-1 may be subscribed to telecom services provided by at least one telecom service provider.
[0042] The base station 104 can be a Evolved NodeB (eNB) or a Home Evolved NodeB
(HeNB) or radio interface for LTE network environment 100. Each telecom service provider may
use one PLMN for amongst the PLMNs 102 to provide telecom services to the subscribers.
I00431 In one implementation, the PLMN 102 may be implement an IP based network. The
PLMN 102 can communicate to other individual networks, interconnected with each other and
functioning as a single large network (e.g., the internet or an intranet). Examples of such individual
networks include, but are not limited to, Global System for Mobile Communication (GSM)
network, Universal Mobile Telecommunications System (UMTS) network, Personal
Communications Service (PCS) network, Time Division Multiple Access (TDMA) network, Code
Division Multiple Access (CDMA) network, and Next Generation Network (NGN). Depending on
the technology, the PLMN 102 includes various network entities, such as gateways, mobility
management entities (MME); however, such details have been omitted for ease of understanding.
[0044] In one implementation, each PLMN, such as the PLMN 102- 1 comprises several
network elements including MME and Serving Gateway (S-GW) (not shown in the figure). The
MME provides control plane functions for access network of the LTE communication environment
100 and the base station 104 communicates to the MMEs of the PLMNs 102 over a S 1 -MME
interface. The protocol used between the MME and the UE over the S 1 -MME interface is called
the S 1 Application Part (S 1AP) protocol. S 1 AP provides the protocol for control plane signaling
between the base station 104 and the MME. S 1 AP uses an underlying transport layer protocol
called Stream Control Transmission Protocol (SCTP).
[0045] The S-GW network element provides user plane connectivity, and forwards packets
to and from the base station 104. The base station 104 communicates to the S-GW of the PLMN
102- 1 over a S 1 -U interface. A person skilled in the art would appreciate that other interfaces and
other network elements are also utilized for communication in a LTE communication network 100.
However, other protocols have not been mentioned, for the sake of brevity.
[0046] In one implementation, the PLMNs 102 share the base station 104 to provide
telecom services to their subscribers. The base station 104 may be connected to PLMNs 102 using
various interfaces. These interfaces have to be active or in a 'connected: state for a subscriber
associated to the UEs 106 to use telecom services provided by the telecom service provider
associated with the PLMNs 102. In other words, a subscriber using the UE 106- 1 can make a voice
call when the connection between the base station 104 and the PLMN associated with the telecom
service provider of the subscriber, say PLMN 102-1, is active or is in the 'connected' state.
[0047] In certain scenarios, the connection between the base station 104 and a PLMN from
amongst the PLMNs 102 may go down and is considered to be in a 'Disconnected' state. In other
words, the subscriber using the UE 106-1 may not be able to utilize telecom services, such as
making or receiving voice calls, when the connection between the base station 104 and the PLMN
102-1 is not active or is in a 'disconnect' state.
[0048] Several scenarios may lead to connectivity failure between the base station 104 and
the PLMNS 102 that may lead to the 'disconnected' state of the interfaces between the base station
104 and the PLMNs 102. In one scenario, the S 1 -MME connection may become unavailable,
where the base station 104 looses connectivity with the MME of the PLMN and cannot
communicate with the MME. In another scenario, the Sl -U interface may become unavailable,
where the base station 104 looses connectivity with the S-GW. Further, in certain scenarios, both
the interfaces, S 1 -MME and S 1 -U may become unavailable where the base station 104 may not be
able to interface with any of the MME and the S-GW. In yet another scenario, although the SCTP
association of base station 104 with the MME may be active, the S 1 AP application may not be
available or may be down and therefore, data from base station 104 may not be forwarded to the
MME.
[0049] In an implementation of the present subject matter, the base station 104 may
continuously broadcast a "Modified SIB Typel" message. In said implementation, the "Modified
SIB Typel" message, amongst other information such as the PLMN identity list, may include a
PLMN status list, which may provide identifiers related to the connectivity status of each PLMN
from amongst the PLMNs 102 associated with the base station 104. As would be appreciated by
those skilled in the art, the first PLMN in a PLMN identity list providing the list of all PLMNs 102
associated with the base station 104 refers to the primary PLMN of the base station 104. Further,
all the other PLMNs listed in the PLMN identity list are the secondary PLMNs from amongst the
PLMNs 102 associated with the base station 104. In one implementation, the PLMN status list in
the "Modified SIB Typel" message is given as a list of PLMN identifiers, where each identifier is
associated with a connectivity status of a PLMN. The place holder for the connectivity status of
the PLMN 102 with respect to base station 104 may be represented by plmnConnectivity status.
The plmnconnectivity status can be 'plmnAvailable' or 'plmnUnavailable7. The plmnConnectivity
status can be 'plmnAvailable' in case a PLMN from amongst the PLMNs 102 is in 'connected'
state from the base station 104 and, the connectivity status may be 'plmnUnavailable' in case the
PLMN from amongst the PLMNs 102 is in 'disconnected' state fiom the base station 104. For sake
of explanation, although the PLMN 102 may have several other connections, the PLMN
connectivity status may represent the connectivity status between PLMN 102 and the base station
104.
[OOSO] For sake of explanation, it may be considered that the UE 106-1 subscribes to the
services of telecom service provider associated with the PLMN 102- 1. The UE 106-2 subscribes to
the services of telecom service provider associated with the PLMN 102-2 and so on. Also, for the
ease of explanation, it is considered that the PLMN 102-1 is the primary PLMN and other PLMNs
102 other than the PLMN 102-1 are the secondary PLMNs.
[OOSl] According to an implementation of the present subject matter, the base station 104
may include an encoding module 108. The encoding module 108 may be configured to encode
information in the base station 104 into a suitable predetermined data structure, such as the
"Modified SIB typel" message, for broadcasting by the base station 104. The encoding module
108 may determine relevant information with regard to each PLMN and encode the determined
information. The relevant information, could include connectivity status associated with each
PLMN from amongst the PLMNs 102.
[0052] The UEs 106 may include a decoding module 1 10. In one implementation, the
decoding module 1 10 may be configured to decode a message received by the UE 106, such as, the
"Modified SIB Typel ". As would be appreciated by those skilled in the art that the messages
broadcasted by the base station 104 may be received by the UEs 106. The decoding module 1 10
may be configured to decode such messages, received by UE 106. In one implementation, the
decoding module 110 may be configured to decode the "Modified SIB Typel" to determine the
connectivity status associated with each PLMN 102 associated with the base station 104. Further,
based on the information decoded by the decoding module 110 from the "Modified SIB Typel ",
the UE 106 may determine a suitable base station to camp on.
[0053] Fig. 2 illustrates data exchange between different network elements of a LTE
communication network to establish connectivity for a subscriber. In many cases, multiple network
entities besides those shown may be configured between the entities, including transmitting
stations, switching stations, and communication links, although those have been omitted for
clarity. Similarly, various acknowledgement and confirmation network responses may also be
omitted for the sake of clarity. The Fig. 2 is used to explain with greater clarity, elements relevant
to the present subject matter.
[0054] The different components of the base station 104 and a UE, such as the UE 106 are
shown in Fig. 2. It would be understood that the base station 104 and the UE 106, or equivalents
thereof, may be implemented in a different manner, without digressing from the scope and spirit of
the present subject matter. Further, although the description of Fig. 2 has been provided with
respect to an LTE communication network, it will be understood that the provision of connectivity
could occur in other wireless environments, for example, GPRS and UMTS networks.
[0055] The functions of the base station 104 and the UE 106-1 may be complementary to
each other. Components relevant to the subject matter with respect to the base station 104 and the
UE 106-1 have been shown in the figure for the ease of explanation. The base station 104 and the
UE 106-1 each include processors 202-1,202-2, respectively and are collectively referred to as
processor(s) 202 hereinafter. The processor(s) 202 may be implemented as one or more
microprocessors, microcomputers, microcontrollers, digital signal processors, central processing
units, state machines, logic circuitries, andlor any devices that manipulate signals based on
operational instructions. Among other capabilities, the processor(s) 202 is configured to fetch and
execute computer-readable instructions stored in the memory.
[0056] The functions of the various elements shown in the figure, including any functional
blocks labeled as "processor(s)", may be provided through the use of dedicated hardware as well
as hardware capable of executing software in association with appropriate software. When
provided by a processor, the functions may be provided by a single dedicated processor, by a
single shared processor, or by a plurality of individual processors, some of which may be shared.
Moreover, explicit use of the term "processor" should not be construed to refer exclusively to
hardware capable of executing software, and may implicitly include, without limitation, digital
signal processor (DSP) hardware, network processor, application specific integrated circuit
(ASIC), field programmable gate array (FPGA), read only memory (ROM) for storing software,
random access memory (RAM), non-volatile storage. Other hardware, conventional andlor custom,
may also be included.
[0057] Also, the base station 104 and UE 106-1 include interface(s) 204-1,204-2,
collectively referred to as interfaces 204. The interfaces 204 may include a variety of software and
hardware interfaces that allow the UE 106-1 and the base station 104 to interact with each other.
Further the base station 104 may also contain software and hardware interfaces to interact with the
LTE communication network. Further, the interface(s) 204 may enable the base station 104 to
communicate with other communication and computing devices, such as web servers, other
wireless networks and external repositories. The interfaces 204 may facilitate multiple
communications within a wide variety of networks and protocol types, including wire networks,
for example LAN, cable, etc., and wireless networks, for example WLAN, cellular, satellite-based
network, etc.
[OOSS] The base station 104 and the UE 106- 1, may hrther include one or more memory
components, referred to as memory 206-1 and 206-2, respectively. The memory 206-1 and 204-3
are collectively referred to as memories 206 hereinafter. The memories 206 may include any
computer-readable medium known in the art including, for example, volatile memory, such as
static random access memory (SRAM) and dynamic random access memory (DRAM), andlor nonvolatile
memory, such as read only memory (ROM), erasable programmable ROM, flash
memories, hard disks, optical disks, and magnetic tapes. The memories may also be computer
readable medium that may include any computer-readable medium known in the art including, for
example, volatile memory, such as random access memory (RAM) and/or non-volatile memory,
such as flash.
[0059] The base station 104 and the UE 106- 1 may also include modules 208- 1,208-2 and
data 2 10- 1,2 10-2, respectively, collectively referred to as modules 208 and data 2 10, respectively.
The modules 208 include routines, programs, objects, components, data structures, and the like,
which perform particular tasks or implement particular abstract data types. The modules 208
enable the present subject matter on the base station 104 and the UE 106-1. Several other modules,
such as the operating system, may be necessary for the functioning of the base station 104 and the
UE 106-1. The modules 208 supplement such modules on the base station 104 and the UE 106- 1.
The data 210 serves, amongst other things, as a repository for storing data that may be fetched,
processed, received, stored, cached or generated by one or more of the modules 208.
[0060] In an implementation, the modules 208-1 of the base station 104 include a
connectivity determination module 2 12, an encoding module 108, a broadcasting module 2 16 and
other module(s) 2 18- 1. In said implementation, the data 2 10- 1 of the base station 104 includes
network data 220, broadcasting data 222, and other data 224- 1. The other module(s) 2 1 8- 1 may
include programs or coded instructions that supplement applications and functions, for example,
programs in the operating system of the base station 104, and the other data 224-1 comprise data
corresponding to one or more other module(s) 208-1.
[0061] According to an implementation of the present subject matter, the base station 104
is shared by multiple PLMNs, such as the PLMNs 102. It may be assumed for the sake of
explanation that the subscriber utilizing the UE 106-1 may have subscribed to telecom services of
telecom service provider associated with the PLMN 102- 1 and, communicates with the base
station 104 to avail the telecom services.
[0062] In one implementation of the present subject matter, the determination module 2 12
of the base station 104 is configured to determine a connectivity status for the PLMNs 102
associated with the base station 104. In said implementation, the connectivity determination
module 21 2 may determine the connectivity status for each PLMN associated with the base station
104 based on the S 1 -MME connection. As described earlier, the S 1 -MME connection determines
the connectivity among the PLMN and their corresponding MMEs. The base station 104 sends
messages which are initiated from UE 106 to the MME over S 1 -MME. In case of MME not
responding to the message sent by the base station 104, the message is resent to check for
response. The message is resent either till there is a response from the MME or for a
predetermined number of times. If there is no response from MME for the messages sent and
resent for the predetermined number of times, then the base station 104 may be interpreted not to
have connectivity to the PLMN 102. In another implementation of the present subject matter, the
connectivity determination module 2 12 may determine the connectivity of the S I -U interface. The
S 1 -U interface may define the connectivity between the base station 104 the S-GW of the LTE
communication network. In yet another implementation of the present subject matter, the
connectivity determination module 2 12 may determine the connectivity status of the PLMN based
on connection of the S 1 AP application. It would be appreciated by those skilled in the art that the
S 1AP application may become inactive even though the SCTP association of base station 104 with
the MME may be active. Therefore, the connectivity determination module 2 12 may determine the
connectivity status associated with the PLMNs 102 associated with the base station 104 based on
various interfaces. In one implementation, the connectivity determination module 212 is
configured to determine the connectivity status associated with the PLMNs 102 periodically.
Further, the periodicity of the determination of the connectivity status may be decided by a
predetermined value.
[0063] In one implementation of the present subject mater, the encoding module 108 of the
base station 104 is configured to encode the connectivity status associated with the PLMNs 102
and generate a "Modified SIB typel" message. In said implementation, the encoding module 108
may also encode other information into the "Modified SIB typel" message, such as tracking area
code, cellBarred status, and other network parameters included in a SIB typel message. Table 1
depicts an exemplary data structure of the "Modified SIB Typel" message generated by the
encoding module 108. The depicted data structure is indicative of parameters broadcasted by the
base station 104 along with the connectivity status in the "Modified SIB Typel" message.
Field Value
Plmn-IdentityList
Explanation
1 to n PLMN identifiers, each plmnIdentity associated
with connectivitystatus and
CellReservedForOperatorUse
cellAccessRelatedInfo
/ infiaFreqReselection I Used to control cell reselection to intra-frequency cells I
I I
1 when the highest ranked cell is barred or treated as the 1
TrackingAreaCode
cellIdentity
TrackingAreaCode (TAC) is common across all PLMNs
cellIdentity (28 bits)
/ if it is a CSG member cell, if selected during manual /
I
selection or to obtain limited service
Csg-Indication If set to TRUE the UE is only allowed to access the cell
Csg-Identity
I the maximum power according to the UE capability.
Identity of the closed subscriber group the cell belongs
to
p-Max
I Defined maximum UL power
q-RXLevMinOffset Integer (1. .8)
Value applicable for the cell. If absent the UE applies
I I
SchedulingInfoList
I I
I Sis. Unit in milliseconds, where m sl denotes 1
Si-Periodicity
Tdd-Config
si-windowlength
Field mandatory for TDD; it is not present for FDD and
the UE shall delete any existing value for this field
Common System information scheduling window for all
Table I
systemInfoValueTag
millisecond
Common for all system information blocks
[0064] The "Modified SIB type 1 " message specifies information that the base station 104
broadcasts. Specifically, the "Modified SIB type 1 " message contains cell related information
including a PLMN identity list providing a list of PLMNs associated with the base station 104.
Further, at least one PLMN identity may be associated with a connectivity status to indicate
interface status of the PLMN the least one PLMN. Furthermore, each PLMN identity may also be
associated with a flag cellReservedForOperatorUse. It would be appreciated that the PLMN
identity list contains the identities of the PLMNs that share the base station 104. It would also be
appreciated that the cellReservedForOperatorUse is set to 'reserved' if the telecom service
provider associated with the particular PLMN has reserved the PLMN and is not open to all
subscribers.
[0065] In an implementation of the present subject matter, the cell related information may
also contains cellIdentity, which uniquely identifies the base station. Further, the cell related
information includes tracking area code, which is common across all PLMNs. Another parameter
included in cell related information includes the cellBarred flag. The cellBarred flag may be used
to define that the base station 104 is available for the UEs 106 to camp on it or not. As would be
appreciated by those skilled in the art, the SIB type 1 message includes the cellBarred flag for the
base station and not for a particular PLMN. Therefore, the cellBarred flag is common across all
PLMNs. Similarly, the "Modified SIB typel" message may also include a cellBarred flag which is
common across all PLMNs 102 associated with the base station 104.
[0066] Hence, according to the present subject matter, the "Modified SIB typel" includes
the connectivity status along with each of the PLMNs in the PLMN Identity list contained in the
base station related information of "Modified SIB typel". The connectivity status associated with
the PLMNs of the PLMN identity list indicates whether a particular PLMN is in 'connected' state
or in 'disconnected' state with respect to the base station 104. According to another
implementation of the present subject matter, the "Modified SIB typel" may utilize the cellBarred
parameter for each PLMN to indicate connectivity status of the PLMN. The cellBarred parameter
may be set with the value "barred" against each PLMN to indicate that the PLMN is in the
"disconnected state with respect to base station 104. The cellBarred parameter may be set to a
value "notBarred" to indicate that the particular PLMN is in "connected" state with respect to base
station 104.
[0067] According to another embodiment of the present subject matter, the "Modified SIB
typel" includes a connectivity status flag only for the first PLMN or the primary PLMN of the
PLMN Identity List contained in the cell related information of "Modified SIB typel". In said
embodiment, if a secondary PLMN is determined to be in a "disconnect" state by the connectivity
determination module 2 12, the PLMN identity may be removed from the PLMN identity list.
[0068] In operation, the encoding module 108 may encode the connectivity status of a
PLMN based on plmnConnectivity status. The plmnConnectivity status can be 'plmnAvailable' or
'plmnunavailable'. The plmnConnectivity status can be 'plmnAvailable' in case a PLMN from
amongst the PLMNs 102 is in 'connected' state from the basa station 104 and, the connectivity
status may be 'plmnUnavailable7 in case the PLMN from am@ngsthe PLMNs 102 is in
'disconnected' state from the base station 104. In said implementation, the PLMN Identity list may
be associated with the connectivity status in the following dedicted manner: ((primary
plmnIdentity, plrnnConnectivity status), (secondaryl plmnIdefitity, plmnConnectivity status),
(secondary;! plmnIdentity, plmnConnectivity status)).
[0069] Similarly, the encoding module 108 may encode the connectivity status of the
PLMN in binary form where the plmnconnectivity status is represented by '1 ' or '0'. The
plmnConnectivity status may be represented as binary value ' 1 ' in case a PLMN from amongst the
PLMNs 102 is in 'connected' state from the base station 104 @d, the connectivity status may be
represented as the binary value '0' in case the PLMN from dongst the PLMNs 102 is in
'disconnected' state from the base station 104.
[0070] In one implementation of the present subject qatter, the broadcasting module 2 16 is
configured to broadcast the "Modified SIB typel" message. $he "Modified SIB typel" message
may include the information included in a typical SIB type 1 qhessage along with the connectivity
status of the PLMNs. As described earlier, the connectivity stbtus may either be associated with all
the PLMNs associated with the base station 104 or, may be aqsociated with only the primary
PLMN associated with the base station 104. In said implemedtation, the broadcast of the
"Modified SIB typel " message by the broadcasting module 2 b 6 may occur after every predetermined
time interval.
[0071] According to an implementation of the present subject matter, the UEs 106, such as
the UE 106- 1 may receive the broadcasted "Modified SIB typje 1" message. In said
implementation, the modules 208-2 of the UE 106-1 include a receiving module 226, a decoding
module 1 10, an updating module 230, and other module(s) 21 8-2. In said implementation, the data
2 10-2 of the UE 106-1 includes cell data 232, cache data 234, and other data 224-2. The other
module(s) 21 8-2 may include programs or coded instructions that supplement applications and
functions, for example, programs in the operating system of the UE 106- 1, and the other data 224-
2 comprise data corresponding to one or more other module(s) 208-2.
[0072] The receiving module 226 of the UE 106-1 is configured to receive the "Modified
SIB type 1" message broadcasted by the base station 104. The receiving module 226 may receive
the broadcasted message when the UE 106-1 powers on, or when the UE 106-1 is in base station
selection or reselection mode. The UE 106-1 is in base station selection or reselection mode when
the UE 106-1 moves outside the range of the base station and tries to camp onto another base
station, or does not establish connectivity with its PLMN, through the base station. It would be
understood by those skilled in the art that the receiving module 226 may receive the "modified SIB
typel" message from several base stations, such as the base station 104, in the vicinity. Based on
the "Modified SIB typel" message, the UE 106-1 may determine the connectivity status associated
with the PLMN to which the UE 106-1 wishes to connect to.
[0073] In operation, the decoding module 1 10 of the UE 106-1 is configured to decode the
"Modified SIB typel" message, as received by the receiving module 224. Based on the "Modified
SIB type 1 " message, the decoding module 1 10 may interpret the connectivity associated with the
PLMN Identity list to determine a base station to connect to. As described earlier, the PLMN status
list contains information about the PLMN identifiers, which share the base station 104. The
decoding module 1 10, in one implementation may also decode the connectivity status associated
with the PLMN identity list in the "Modified SIB typel" message.
[0074] In one implementation, the decoding module 1 10 may decode the information
encoded by the encoding module 108. For example, if the encoding module 108 encodes the base
station related information using PLMN identity list as a list of string identifiers, and the
connectivity status of PLMN as enumerated data type, then the decoding module 1 10 may decode
the PLMN identity list as the string identifiers and the connectivity status of PLMN as enumerated
data types.
[0075] The UE 106-1 also includes the updating module 230 for updating the UE 106-1
with the latest connectivity status information associated with the PLMNs 102. In one
implementation, the UE 106- 1 stores the connectivity status decoded from the received "Modified
SIB typel" message for a pre-determined duration of time. The updating module 230 uses data
received by the decoding module 1 10. If the most recent connectivity status, or the connectivity
status received in the "Modified SIB typel" message with the most recent time stamp is different
from the connectivity status stored by the UE 106-1, the updating module 230 is configured to
update the connectivity status for the UE 106-1. In one implementation, the updating module 230
may update the connectivity status information after every pre-defined time interval.
[0076] For example, consider that the receiving module 226 receives a "Modified SIB
type 1 " message at time t. Then, the decoding module 1 10 decodes the "Modified SIB type 1 "
message to determine various parameters including the connectivity status associated with the
PLMN Identity list. If at time t, the connectivity status received was {(PLMN 102-1,
AVAILABLE), (PLMN 102-2, AVAILABLE)), the updating module 230 may then update the
connectivity status at time (t+x). It may so happen that at time (t+x), the "Modified SIB typel"
message received by the receiving module 226 may include the connectivity status as {(PLMN
102- 1, UNAVAILABLE), (PLMN 102-2, AVAILABLE)). In such a scenario, the updating
module 230 may update the connectivity status associated with the PLMN 102-1 in the UE 106-1
The UE 106-1 may use the updated information to determine the base station on which the UE
106-1 may camp, considering that the PLMN 102-1 has been indicated to be in state
'disconnected' from the base station 104.
[0077] Fig. 3(a) and 3(b) illustrates methods 300 and 350 for providing connectivity to
subscribers in an LTE communication network, according to an embodiment of the present subject
matter. The order in which the methods 300 and 350 are described is not intended to be construed
as a limitation, and any number of the described method blocks can be combined in any order to
implement the method 300 and 350, or any alternative methods. Additionally, individual blocks
may be deleted from the methods without departing from the spirit and scope of the subject matter
described herein. Furthermore, the methods can be implemented in any suitable hardware,
software, firmware, or combination thereof.
[0078] The method(s) may be described in the general context of computer executable
instructions. Generally, computer executable instructions can include routines, programs, objects,
components, data structures, procedures, modules, functions, etc., that perform particular functions
or implement particular abstract data types. The methods may also be practiced in a distributed
computing environment where functions are performed by remote processing devices that are
linked through a communications network. In a distributed computing environment, computer
executable instructions may be located in both local and remote computer storage media, including
memory storage devices.
LO0791 A person skilled in the art will readily recognize that steps of the methods can be
performed by embedded systems. Herein, some embodiments are also intended to cover embedded
storage devices, which are machine or computer readable and encode machine-executable or
computer-executable programs of instructions, where said instructions perform some or all of the
steps of the described method. The embodiments are also intended to cover both communication
network and communication devices configured to perform said steps of the exemplary methods.
[OOSO] Referring to Fig. 3(a), the method 300 may be implemented by a base station. At
block 302, the method includes identifying a list of public land mobile networks (PLMNs) sharing
the base station, where the list of PLMNs includes a primary PLMN.
[OOSl] At block 304, a connectivity status of at least the primary PLMN from the list of
PLMNs is determined. In one implementation, the connectivity status is indicative of whether the
PLMN provides user plane functions to User Equipments (UEs) utilized by subscribers associated
with the telecom service provider. In one implementation, the connectivity status may either be
available or un-available. The connectivity status 'available' may indicate that the at least the
primary PLMN is capable of providing user plane functions to the UEs of the subscribers.
Similarly, the connectivity status 'un-available' may indicate that the at least the primary PLMN is
not capable of providing user plane functions to the UEs of the subscribers. In one implementation
of the present subject matter, the connectivity status is represented as plrnnConnectivity status
parameter. In the given implementation, the plmnConnectivity status parameter can be assigned
one of values 'plmnAvailable' and 'plmnUnavailable'. The connectivity status 'available' is
defined as 'plmnAvailable' and the connectivity status 'un-available' is defined as
'plmnUnavailable'. Further, in one implementation, the connectivity status of the at least the
primary PLMN 102- 1 is determined by ascertaining availability of S 1 -MME interface, which
interfaces between the base station 104 and the Mobility Management Entity, between the at least
the primary PLMN and the base station 104.
(00821 Further, the connectivity status of the at least the primary PLMN 102- 1 is
determined based on availability of S 1 -U interface. The S 1 -U interface is the interface between a
Packet Data Network Gateway (PDN-GW) and the base station 104. If the SI-U interface is not
available, then the plmnConnectivity status parameter is set to plmnunavailable. In another
implementation, the connectivity status of the at least the primary PLMN 102-1 is determined
based on the availability of S 1 application protocol (S 1AP) can also be determined. If S 1AP
communication is not active, the plmnconnectivity parameter status is set to plmnunavailable.
[0083] In one implementation, the plmnConnectivity status parameter is determined to be
plmnAvailable, if all the interfaces S 1 -MME and S 1 -U are available and the S 1 AP communication
is active. The base station 104 determines the plmnConnectivity status parameter as
' plrnnunavailable', if any one interface S 1 -MME or S 1 -U interfaces is unavailable or if the S 1 AP
communication is not active. In one implementation, the method at block 304 is implemented by
the connectivity determination module 212 of the base station 104.
[0084] The methods to determine connectivity status described with respect to block 304
are meant to be exemplary, but not exhaustive. The methods to determine connectivity status given
above may be used in conjunction with other methods or may be replaced by similar methods with
the objective of determining the connectivity status between each PLMN 102 and the base station
104.
[OOSS] At block 306 the connectivity status of the at least the primary PLMN is encoded
into a "Modified SIB Typel" message. In one implementation, where the "Modified SIB Typel"
message includes information relevant for a user equipment (UE), associated with the subscriber of
telecom service provider, to camp on the base station. In one implementation, the information
encoded into "Modified SIB Typel" message may include the list of PLMNs 102 which includes
at least the primary PLMN, connectivity status of list of PLMNs 102 and information related to
network required by UEs 106 to camp on the base station 104. In one implementation, a cellBarred
flag of the "System Information Block Typel" message is used to encode the connectivity status of
the primary PLMN 102- 1.
[0086] In another implementation, the secondary PLMNs, that is, PLMNs other than the
primary PLMN 102- 1, may be removed from the list of PLMNs if the plmnConnectivity status
parameter is plmnunavailable. In one implementation, the method at block 306 is implemented by
encoding module 108 of the base station I 04.
[0087] At block 308, the "Modified SIB typel" information is broadcasted by the base
station 104. In one implementation, the method at block 3 10 is implemented by broadcasting
module 2 16 of the base station 104.
[0088] Referring to Fig. 3(b), the method 350 may be implemented by a UE 106. At block
352, a "Modified SIB typel" message is received, where the "Modified SIB Typel" message
includes a list of public land mobile networks (PLMNs) sharing a base station, and the list of
PLMNs includes a primary PLMN. In one implementation, "Modified SIB typel" message is
received in a predetermined format and includes a list of PLMNs 102, which includes a primary
PLMN 102- 1 and the "Modified SIB Typel" message also includes a connectivity status
associated with one PLMN in the list of PLMNs.
[0089] At block 354, the connectivity status associated with at least one PLMN from the
list of PLMNs 102 in the "Modified SIB typel" message is decoded. In one implementation the
connectivity status is indicative of whether the at least one PLMN provides user plane hnctions to
subscribers of a telecom service provider. In one implementation, the method at block 354 is
implemented by a decoding module 1 10 of the UE 106.
[0090] At block 356, the decoded connectivity status is used to determine if the UE 106
utilized by subscribers of the telecom service provider can camp on the base station 104. In one
implementation, the UE 106 may decide to camp on the base station 104 if the connectivity status
is 'available'. Other network parameters, like the cellReservedForOperatorUse in "Modified SIB
Typel" message may be considered in addition to the connectivity status to determine whether the
base station 104 may be camped on. In one implementation, if the connectivity status of the PLMN
selected by the UE 106-1 is "un-available", the UE 106 may determine not to camp the base
station 104. In one implementation the method at block 356 is implemented by an updating module
230 of the UE 106.
[0091] Although embodiments for methods and systems for providing connectivity
between subscribers and telecom service providers in a shared LTE communication network have
been described in a language specific to structural features and/or methods, it is to be understood
that the invention is not necessarily limited to the specific features or methods described. Rather,
the specific features and methods are disclosed as exemplary embodiments for providing
connectivity in the LTE communication network.

I We Claim;
1. A method for providing connectivity to User Equipments (UEs) (106) utilized by
subscribers of telecom service providers in a Long Term Evolution (LTE) communication
network, the method comprising:
identifying a plurality of Public Land Mobile Networks (PLMNs) 102 sharing a
base station (104);
determining a cormectivity status associated with at least a primary PLMN (102-1)
from amongst the plurality of PLMNs (102), wherein the connectivity status is indicative
whether the at least the primary PLMN (102-1) provides user plane functions to the
subscribers; and
encoding the cormectivity status determined for the at least the primary PLMN
(102-1) into a "Modified SIB Typel" message, wherein the "Modified SIB Typel"
message comprises information relevant for the UEs (106) to camp on the base station
(104).
2. The method as claimed in claim 1, wherein the method further comprises broadcasting of
the "Modified SIB Typel".
3. The method as claimed in claim 1, wherein the cormectivity status is represented as
plmnConnectivity status parameter in the "Modified SIB Typel" message.
4. The method as claimed in claim 1, wherein the cormectivity status is one of 'available' and
'unavailable'.
5. The method as claimed in claim 4, wherein the connectivity status 'available' is
represented as plmnAvailable and connectivity status 'unavailable' is represented as
plnmUnavailable.
6. The method as claimed in claim 4, wherein the cormectivity status is represented as
'unavailable', wherein the at least the primary PLMN (102-1) does not provide user plane
functions to the base station 104.
28
7. The method as claimed in claim 1, wherein the determining the cormectivity status is based
on a Sl-MME interface between a Mobility Management Entity (MME) of the at least the primary
PLMN (102-1) and the base station (104).
8. The method as claimed in claim 1, wherein the connectivity status is represented by a
cellBarred parameter of a System Information Block 'SIB' Type 1 message in the "Modified SIB
Typel" message, and wherein the cellBarred parameter is associated with the at least the primary
PLMNs (102-1).
9. A method for cormecting to a LTE communication network, the method comprising:
receiving a "Modified SIB typel" message, wherein the "Modified SIB typel"
message comprises identity of a plurality of Public Land Mobile Networks (PLMNs) (102)
sharing a base station (104), wherein the plurality of PLMNs (102) comprises at least a
primary PLMN (102-1);
decoding a connectivity status associated with at least one PLMN 102 from
amongst the plurality of PLMNs (102) from the "Modified SIB typel" message, wherein
the cormectivity status is indicative of whether the at least one PLMN (102) provides user
plane functions to the subscribers.
10. The method as claimed in claim 9, wherein the method further comprises determining
whether to camp on the base station based on the decoding.
11. A base station (104) for providing connectivity to UEs (106) utilized by subscribers of
telecom service providers in a LTE communication network, the base station (104) comprising:
a processor (202-1);
a cormectivity determination module (212) coupled to the processor (202-1) adapted
to:
identify a plurality of PLMNs (102) sharing a base station (104), wherein
the plurality of PLMNs (102) is associated with the telecom service providers, and
wherein the plurality of PLMNs (102) comprises a primary PLMN (102-1); and
29
determining a connectivity status associated with at least the primary PLMN
(102-1) from amongst the plurality of PLMNs (102), wherein the connectivity
status is indicative whether the at least the primary PLMN provides user plane
functions to the subscribers; and
an encoding module (108) coupled to the processor (202-1), adapted to encode the
connectivity status determined for the at least the primary PLMN (102-1) into a "Modified
SIB Typel" message, wherein the "Modified SIB Typel" message comprises information
relevant for the UEs (106) to camp on the base station (104).
12. The base station (104) as claimed in claim 11, wherein the encoding module (108) is
adapted to remove a PLMN (102) from amongst the at least the primary PLMN (102-1) while
encoding the "Modified SIB Type 1" message, wherein the connectivity status of the PLMN (102)
is indicative that the PLMN (102) does not provide user plane functions to the UEs (106).
13. The base station (104) as claimed in claim 11, wherein the connectivity determination
module (212) is adapted to determine the connectivity status based on a Sl-U interface between a
packet data network gateway (PDN-GW) of the at least the primary PLMN (102-1) and the base
station (104).
14. A UE (106) for cormecting to a LTE communication network, the UE (106) comprising:
a processor (202-2);
a receiving module (226) coupled to the processor (202-2) adapted to receive a
"Modified SIB typel" message, wherein the "Modified SIB typel" message comprises
identity of a plurality of Public Land Mobile Networks (PLMNs) (102) sharing a base
station (104), wherein the plurality of PLMNs (102) comprises at least a primary PLMN
(102-1); and
a decoding module (110) coupled to the processor (202-2) adapted to decode a
connectivity status associated with at least one PLMN (102) from amongst the plurality of
PLMNs (102) from the "Modified SIB typel" message, wherein the connectivity status is
indicative of whether the at least one PLMN (102) provides user plane flinctions to the
subscribers.
30
15. A non-transitory computer readable medium having a set of computer readable instructions
that, when executed, cause a computing system to:
identify a plurality of Public Land Mobile Networks (PLMNs) (102) sharing a base
station (104), wherein the plurality of PLMNs (102) is associated with the telecom service
providers, and wherein the plurality of PLMNs (102) comprises a primary PLMN (102-1);
determine a connectivity status associated with at least the primary PLMN (102-1)
from amongst the plurality of PLMNs (102), wherein the connectivity status is indicative
whether the at least the primary PLMN provides user plane functions to the subscribers;
and
encode the connectivity status determined for the at least the primary PLMN (102-
1) into a "Modified SIB Type!" message, wherein the "Modified SIB Typel" message
comprises information relevant for the UEs 106 to camp on the base station (104).