FIELD OF THE INVENTION

The present invention relates to the field of Millimeter-Wave Mobile Broadband (MMB) system  and more particularly relates to a method and apparatus for communicating data packets in a cloud cell.

BACKGROUND OF THE INVENTION

Millimeter-Wave Mobile Broadband (MMB) system is a millimeter wave based system which operates in a radio frequency range of 30 Gigahertz (GHZ) and 300 GHz. MMB system uses radio waves with wavelength in range of 1 millimeter (mm) to 10mm and is a candidate for next generation mobile communication technology due to considerable amount of spectrum available in mmWave band.

Generally  in a MMB system  MMB base stations are deployed with higher density than macro-cellular base stations in order to ensure good network coverage. This is possible as transmission and reception of signals is based on narrow beams which suppress interference from neighbouring MMB base stations and extend the range of an MMB link.

Typically  in a MMB network  multiple MMB base stations form a grid with a large number of nodes with which a mobile station can communicate  thereby ensuring high quality equal grade of service (EGOS) irrespective of the location of the mobile station. The grid having a plurality of MMB base stations serving a mobile station is commonly termed as virtual cell or cloud cell. In a could cell  the multiple base stations communicating with the mobile stations need to perform downlink transmission beamforming while the mobile stations communicating with the base stations need to perform downlink reception beamforming for receiving downlink control information and data packets. Similarly  a mobile station communicating with a base station in a cloud cell may need to perform uplink transmission beamforming while the base station needs to perform uplink reception beamforming for transmitting uplink data.

Further  in a cloud cell  one of the base stations acts a master base station and remaining base stations acts slave base stations with respect to the mobile station. In overlapping cloud cell scenario  a base station can be a part of more than one cloud cells. In one cloud cell  the base station acts as a master base station for one mobile station and in another cloud cell  the base station act as a slave base station for another mobile station.

In a conventional cellular system  in which a mobile station communicates with a single base station  the base station receives data packets from the IP network via data gateway in downlink  performs Medium Access Control (MAC) and Physical (PHY) processing of the data packets and transmits physical burst carrying the processed data packets to the mobile station. In the uplink  the base station receives physical bursts from the mobile station  performs PHY and MAC processing of the physical bursts  and transmits data packets to an Internet Protocol (IP) network via the data gateway.

In another conventional cellular system  in which a mobile station communicates with a base station via a relay station  the base station receives data packets from the IP network via data gateway in downlink  performs MAC processing of the data packets and transmits MAC Protocol Data Units (PDUs) to the relay station. The relay station performs PHY processing of the MAC PDUs and transmits the physical bursts carrying the MAC PDUs to the mobile station. In the uplink  the relay station receives the physical burst from the mobile station  performs PHY processing of the physical burst and transmits the MAC PDUs received in the physical bursts to the base station so that the base station transmits the data packets containing the MAC PDUs to the data gateway.

However  in a cloud cell environment  since multiple base stations are grouped together to serve a mobile station and the mobile station communicates with multiple base stations in a cloud cell  it is desirable to address problems associated with routing data packets from the IP network to the mobile station through the base station(s) in the cloud cell  processing of data packets across the base station(s) in the cloud cell in downlink and uplink and routing data packets from the mobile station to the IP network through the base station(s) in the cloud cell.

SUMMARY OF THE INVENTION

The present invention provides a method and apparatus for communicating data packets in a cloud cell. In one aspect  a method includes identifying a first network node from which at least one data packet intended for a mobile station in a cloud cell is received by a base station  where the first network node may include one of a data gateway and a master base station of the cloud cell.

The method further includes identifying a second network node in the cloud cell to which the at least one data packet is to be sent if the at least one data packet is received from the data gateway  where the second network node includes one of the mobile station and one of slave base stations of the cloud cell. Furthermore  the method includes performing entire processing of the at least one data packet received from the data gateway and transmitting the entirely processed data packet to the mobile station if the second network node is the mobile station.

Alternatively  the method includes performing partial processing of the at least one data packet received from the data gateway if the second network node is said one of the slave base stations and transmitting the partially processed data packet to said one of the slave base stations so that said one of the slave base stations entirely processes the partially processed data packet and transmits the entirely processed data packet to the mobile station. Moreover  the method includes performing entire processing of the at least one data packet if the at least one data packet is received from the master base station and transmitting the entirely processed data packet to the mobile station  where the at least one data packet received from the master base station is a partially processed data packet.

In another aspect  a base station includes a processor and memory coupled to the processor  where the memory includes a packet manager configured for performing the method described above.

In yet another aspect  a method of a base station for uplink data transmission in a cloud cell includes identifying a first network node in a cloud cell from which at least one data packet intended for an Internet Protocol (IP) network is received by a base station  where the first network node includes one of a mobile station and one of slave base stations. The method further includes identifying a second network node to which the at least one data packet is to be sent if the at least one data packet is received from the mobile station  where the second network node includes one of a data gateway and a master base station of the cloud cell.

Furthermore  the method includes performing complete processing of the at least one data packet received from the mobile station and transmitting the completely processed data packet to the data gateway if the second network node is the data gateway. Alternatively  the method includes performing partial processing of the at least one data packet received from the mobile station if the second network node is the master base station and transmitting the partially processed data packet to the master base station so that the master base station entirely processes the partially processed data packet and transmits the entirely processed data packet to the data gateway.

Moreover  the method includes performing entire processing of the at least one data packet if the at least one data packet is received from said one of the slave base stations and transmitting the entirely processed data packet to the data gateway  where the at least one data packet received from said one of the slave base stations is a partially processed data packet.

In further another aspect  a base station includes a processor and memory coupled to the processor  where the memory includes a packet manager configured for performing the method described above.

Other features of the embodiments will be apparent from the accompanying drawings and from the detailed description that follows.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

Figure 1 is a schematic diagram illustrating a cloud cell environment  according to one embodiment.

Figure 2 is a process flowchart illustrating an exemplary method of downlink communication of data packets in the cloud cell environment by a base station  according to one embodiment.

Figure 3 is a process flowchart illustrating an exemplary method of uplink communication of data packets in the cloud cell environment by a base station  according to one embodiment.

Figures 4A and 4B are schematic representations illustrating Medium Access Control (MAC) layer and Physical (PHY) layer processing performed by a base station in uplink and downlink  in the context of the invention.

Figure 5 is a process flowchart illustrating a detailed method of downlink communication of data packets in the cloud cell environment by a base station  according to one embodiment.

Figures 6A-6C are schematic representations illustrating downlink communication of data packets in the cloud cell environment by a base station  according to one embodiment.

Figure 7 is a process flowchart illustrating a detailed method of uplink communication of data packets in the cloud cell environment by a base station  according to one embodiment.

Figures 8A-8C are schematic representations illustrating uplink communication of data packets in the cloud cell environment by a base station  according to one embodiment.

Figure 9 is a process flowchart illustrating a detailed method of downlink communication of data packets in the cloud cell environment by a base station  according to another embodiment.

Figures 10A-10C are schematic representations illustrating downlink communication of data packets in the cloud cell environment by a base station  according to another embodiment.

Figure 11 is a process flowchart illustrating a detailed method of uplink communication of data packets in the cloud cell environment by a base station  according to another embodiment.

Figures 12A-12C are schematic representations illustrating uplink communication of data packets in the cloud cell environment by a base station  according to another embodiment.

Figure 13 illustrates a block diagram of a base station showing various components for implementing embodiments of the present subject matter.

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a method and apparatus for communicating data packets in a cloud cell. In the following detailed description of the embodiments of the invention  reference is made to the accompanying drawings that form a part hereof  and in which are shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention  and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present invention. The following detailed description is  therefore  not to be taken in a limiting sense  and the scope of the present invention is defined only by the appended claims.

Figure 1 is a schematic diagram illustrating a cloud cell environment 100  according to one embodiment. The cloud cell environment 100 includes a plurality of cloud cells 110A-N. For the purpose of illustration  two cloud cells viz. the cloud cell 110A and the cloud cell 110B are depicted in Figure 1. The cloud cell 110A includes a multiple base stations (BSs) 106A-C serving a mobile station (MS) 108A. In the cloud cell 110A  the BS 106C is assigned a role of a master and remaining BSs 106A-B acts as a slave BS. Similarly  the cloud cell 110B includes multiple BSs 106C-F serving a MS 108B. In the cloud cell 110B  the BS 106E is a master BS while the remaining BSs 106C-D and 106F acts as slave BSs. As depicted in Figure 1  the BS 106C is a master BS for the cloud cell 110A and is a slave BS for the cloud cell 110B. It can be noted that  BSs in a cloud cell and a master BS keep changing based on the movement of MS.

In each of the cloud cells 110A-N  a master BS can directly communicate data packets with a data gateway 104 while a slave BS communicates with the data gateway via the master BS. The master BS may be physically or logically connected to the data gateway 104. The data gateway 104 may be a logical entity residing in one of BSs in a wireless communication network. The data gateway 104 may be directly connected to an Internet Protocol (IP) network or connected via other network nodes. Also  the master BS in the cloud cell can directly communicate data packets with MS or via another slave BS.

According to the present invention  the BSs 106A-F processes data packets intended for data gateway 104/MS 108A-B based on a source network node (e.g.  data gateway  master BS  slave BS or MS) from which the data packets are received and a destination network node (e.g.  data gateway  master BS  slave BS or MS) to which the data packets are to be sent. It is appreciated that  each BS in a cloud cell environment 100 is capable of performing entire data packet processing functions on data packets in downlink as well as uplink. The detailed steps of processing and transmitting/receiving data packets by a master/slave BS in uplink and downlink are described in the following description.

Figure 2 is a process flowchart 200 illustrating an exemplary method of downlink communication of data packets in the cloud cell environment 100 by a BS  according to one embodiment. Consider that  at step 202  data packets are received from a network node by the BS 106C. At step 204  the network node from which the data packets are received is identified by the BS 106C. For example  the BS 106C may receive the data packets directly from the data gateway 104 if the BS 106C acts a master BS of the CC 110A. However  the BS 106C may receive the data packets from the BS 106E  which is master BS in the CC 110B  if the BS 106C acts as a slave base station with respect to the cloud cell 110B.

If the data packets are received from the data gateway 104  at step 206  a network node to which the data packets to be sent is identified. For example  the BS 106C may send the data packets directly to the MS 108A. Alternatively  the BS 106C may send the data packets to another BS (e.g.  the BS 106A) which is a slave BS in the CC 110A.

If the data packets are to be sent to the BS 106A  at step 208  partial processing of the data packets is performed by the BS 106C. In one embodiment  in partially processing the data packets  the BS 106C generates the Medium Access Control (MAC) Service Data Units (SDUs) from the data packets received from the data gateway 104  generates Automatic Repeat Request (ARQ) blocks from the MAC SDUs  and generates MAC Protocol Data Units (PDUs) by applying the fragmentation and packing function on the ARQ blocks or MAC SDUs. It can be noted that  the security function is optional and if enabled  the BS 106C generates encrypted MAC SDUs from the data packets received from the data gateway 104. The BS 106C processes the MAC SDUs (encrypted or unencrypted) using an ARQ function to generate the ARQ blocks. The ARQ function is optional and is not needed for all the MAC SDUs. It is understood that  the BS 106C applies the ARQ function for the MAC SDUs of an ARQ enabled connection. The BS 106C then generates the MAC PDUs by applying fragmentation and packing function on the ARQ blocks for the ARQ enabled connection. It can be noted that  a single MAC PDU upon applying the fragmentation and packing function consists of one ARQ block fragment or multiple ARQ block fragments and/or unfragmented ARQ blocks.

Alternatively  for an ARQ enabled connection  the BS 106C applies fragmentation and packing function on the MAC SDUs to generate the ARQ block. In this case  the BS 106C does not apply fragmentation and packing function on the ARQ block to generate the MAC PDUs. In case of non-ARQ enabled connection  the BS 106C generates the MAC PDUs by applying fragmentation and packing function on the MAC SDUs. It can be noted that  a single MAC PDU upon applying the fragmentation and packing function consists of one MAC SDU fragment or multiple MAC SDU fragments and/or unfragmented MAC SDUs. The BS 106C may also multiplex ARQ blocks or MAC SDUs received from multiple connections in a single MAC PDU in case multiplexing is enabled.

In another embodiment  in partially processing the data packets  the BS 106C generates the MAC SDUs from the data packets received from the data gateway 104 and generates ARQ blocks from the MAC SDUs. It can be noted that  the security function is optional and if enabled  the BS 106C generates encrypted MAC SDUs from the data packets received from the data gateway 104. The MAC SDUs (encrypted or unencrypted) are then processed by ARQ function to generate the ARQ blocks. The ARQ function is optional and may not be needed for all the MAC SDUs. It can be noted that  the BS 106C applies the ARQ function for the MAC SDUs of an ARQ enabled connection.

At step 210  the partially processed data packets and a logical identifier of the MS 108A are transmitted to the slave BS 106A so that the slave BS 106A performs entire processing of the partially processed data packets and transmits the completely processed data packets to the MS 108A based on the logical identifier of the MS 108A.

In one embodiment  in entirely processing the partially processed data packet  the slave BS 106A performs complete PHY layer processing of the partially processed data packet. The slave BS 106A generates one or more Physical (PHY) PDUs from the data packets (i.e.  MAC PDUs) received from the master BS 106C. Then  the BS 106A processes the PHY PDUs using the physical layer processing functions like coding  modulation  interleaving  etc. and transmits the processed PHY PDUs to the MS 108A.

In another embodiment  in entirely processing the partially processed data packets  the slave BS 106A performs the remaining MAC layer processing and complete PHY layer processing of the partially processed data packets. For example  the slave BS 106A generates MAC PDUs by applying fragmentation and packing function on the ARQ blocks for the ARQ enabled connection. Alternatively  for the ARQ enabled connection  the slave BS 106A applies fragmentation and packing function on the MAC SDUs to generate the ARQ block. In this case  the slave BS 106A does not apply fragmentation and packing function to generate the MAC PDUs.

In case of a non-ARQ enabled connection  the slave BS 106A generates MAC PDUs by applying fragmentation and packing function on the MAC SDUs. The BS 106A may also multiplex ARQ blocks or MAC SDUs received from multiple connections in a single MAC PDU if multiplexing is enabled.

Furthermore  the slave BS 106A generates one or more PHY PDUs from the data packets (i.e. MAC PDUs) received from the master BS 106C. Then  the slave BS 106A processes the PHY PDUs using the physical layer processing functions like coding  modulation  interleaving etc and transmits the one or more processed PHY PDUs to the MS 108A.

In one exemplary implementation  the BS 106C sends the logical identifier with the partially processed data packets to the BS 106A when the MS 108A is assigned a single logical identifier. In another exemplary implementation  the BS 106C sends the logical identifier assigned by it with the completely processed data packets when the MS 108A is assigned one logical identifier by each BS in a cloud cell. In this implementation  the BS 106A maintains a mapping between a logical identifier assigned by the BS 106C and a logical identifier assigned by the BS 106A.

In yet another exemplary implementation  the BS 106C sends the logical identifier assigned by the BS 106A with the completely processed data packets when the MS 108A is assigned one logical identifier by each BS in a cloud cell. In this embodiment  the BS 106C maintains a mapping between a logical identifier assigned by the BS 106A and a logical identifier assigned by the BS 106C.

If the data packets are to be sent to the MS 108A  at step 214  complete processing of the data packets is performed by the BS 106C. At step 216  the completely processed data packets are transmitted to the MS 108A. In completely processing the data packets  the BS 106C generates the MAC SDUs from the data packets received from the data gateway 104  generates ARQ blocks from the MAC SDUs  generates MAC PDUs by applying the fragmentation  packing and multiplexing function on the ARQ blocks or the MAC SDUs  generates one or more PHY PDUs from the MAC PDUs  and processes the PHY PDUs using the physical layer processing functions like coding  modulation  interleaving etc.

If at step 204  the network node  from which the data packets are received  is identified as the master BS 106E  then it implies that the BS 106C is a slave BS in the CC 110B and the data packets are partially processed by the BS 106E. Hence  at step 212  complete processing of the partially processed data packets is performed by the BS 106C. At step 216  the completely processed data packets are transmitted to the MS 108B based on the logical identifier of the MS 108B.

In one embodiment  in entirely processing the partially processed data packet  the slave BS 106C performs complete PHY layer processing of the partially processed data packet. The slave BS 106C generates one or more PHY PDUs from the data packets (i.e.  MAC PDUs) received from the master BS 106E. Then  the BS 106C processes the PHY PDUs using the physical layer processing functions like coding  modulation  interleaving  etc. and transmits the processed PHY PDUs to the MS 108B.

In another embodiment  in entirely processing the partially processed data packets  the slave BS 106C performs the remaining MAC layer processing and complete PHY layer processing of the partially processed data packets. For example  the slave BS 106C generates MAC PDUs by applying fragmentation and packing function on the ARQ blocks for the ARQ enabled connection. Alternatively  for the ARQ enabled connection  the slave BS 106C applies fragmentation and packing function on the MAC SDUs to generate the ARQ block. In this case  the slave BS 106C does not apply fragmentation and packing function to generate the MAC PDU.

In case of a non-ARQ enabled connection  the slave BS 106C generates MAC PDUs by applying fragmentation and packing function on the MAC SDUs. The BS 106C may also multiplex ARQ blocks or MAC SDUs received from multiple connections in a single MAC PDU if multiplexing is enabled.

Furthermore  the slave BS 106C generates one or more PHY PDUs from the data packets (i.e. MAC PDUs) received from the master BS 106C. Then  the slave BS 106C processes the PHY PDUs using the physical layer processing functions like coding  modulation  interleaving etc and transmits the one or more processed PHY PDUs to the MS 108B.

Figure 3 is a process flowchart 300 illustrating an exemplary method of uplink communication of data packets in the cloud cell environment 100 by a BS  according to one embodiment. Consider that  at step 302  data packets are received from a network node by the BS 106C. At step 304  the network node from which the data packets are received is identified by the BS 106C. For example  the BS 106C may receive the data packets directly from the MS 108A or MS 108B. Alternatively  the BS 106C may receive the data packets from another BS (e.g.  the BS 106A) which is a slave BS in the CC 110A.

If the data packets are received from the MS 108A or 108B  at step 306  a network node to which the data packets to be sent is identified. The BS 106C sends the data packets directly to the data gateway 104 if the BS 106C has received data packets from the MS 108A in the CC 110A for which BS 106C is the master BS. However  the BS 106C sends the data packets to the BS 106E  which is master BS in the CC 110B  if the BS 106C has received the data packets from the MS 108B in the CC 110B for which the BS 106C is acting as a slave base station.

If the data packets are to be sent to the BS 106E  at step 308  partial processing of the data packets is performed by the BS 106C. In one embodiment  in partially processing the data packets  the slave BS 106C generates PHY PDUs by applying PHY layer processing functions like demodulation  deinterleaving  decoding  etc. on the data packets and generates MAC PDUs from the PHY PDUs. In another embodiment  in partially processing the data packets  the slave BS 106C generates PHY PDUs by applying PHY layer processing functions like demodulation  deinterleaving  decoding  etc. on the data packets and generates MAC PDUs from the PHY PDUs. In case of non-ARQ enabled connection  the slave BS 106C generates MAC SDUs (fragmented or unfragmented) by applying the unpacking function on the MAC PDU. In case of an ARQ enabled connection  the slave BS 106C generates ARQ blocks (fragmented or unfragmented) by applying the unpacking function on the MAC PDU.

At step 310  the partially processed data packets are transmitted to the BS 106E so that the master BS 106E performs complete processing of the partially processed data packets and transmits the completely processed data packets to the data gateway 104. If the data packets are to be sent to the data gateway 104  at step 314  complete processing of the data packets is performed by the BS 106C. At step 316  the completely processed data packets are transmitted to the data gateway 104. In completely processing the data packets  the BS 106C performs the complete MAC layer and PHY layer processing of the data packets. Then  the BS 106C generates the PHY PDUs by applying PHY layer processing functions like demodulation  deinterleaving  decoding etc. on the data packets. The BS 106C generates MAC PDUs from the PHY PDUs using the de-concatenation function. In case of a non-ARQ enabled connection  the BS 106C generates MAC SDUs (fragmented or unfragmented) by applying the unpacking function on the MAC PDU.

In case of an ARQ enabled connection  the BS 106C generates ARQ blocks (fragmented or unfragmented) by applying the unpacking function on the MAC PDU. The BS 106C then generates unfragmented ARQ blocks or MAC SDUs by applying the reassembly function to the fragmented ARQ blocks or MAC SDUs respectively. In case of the ARQ enabled connection  the BS 106C generates MAC SDUs from the ARQ blocks. It can be noted that the BS 106C may optionally apply the security function to the MAC SDUs and generate data packets from the MAC SDUs.

If at step 304  the network node  from which the data packets are received  is identified as the BS 106A  then it implies that the BS 106C is the master BS in the CC 110A and the data packets are partially processed by the BS 106A. Hence  at step 312  complete processing of the partially processed data packets is performed by the BS 106C. At step 316  the completely processed data packets are transmitted to the data gateway 104.

In one embodiment  in completely processing the data packets  the BS 106C performs the complete MAC layer processing on the partially processed data packets (i.e.  MAC PDUs) received from the slave BS 106A. In case of an non-ARQ enabled connection  the BS 106C generates MAC SDUs (fragmented or unfragmented) by applying the unpacking function on the MAC PDU. In case of an ARQ enabled connection  the BS 106C generates ARQ blocks (fragmented or unfragmented) by applying the unpacking function on the MAC PDU. The BS 106C then generates unfragmented ARQ blocks or MAC SDUs by applying the reassembly function to the fragmented ARQ blocks or MAC SDUs respectively. In case of an ARQ enabled connection  the BS 106C generates MAC SDUs from the ARQ blocks. It can be noted that  the BS 106C optionally applies security function to the MAC SDUs and generates data packets from the MAC SDUs.

In another embodiment  in completely processing the data packets  the BS 106C performs the partial MAC layer processing on the partially processed data packets (i.e. MAC SDUs or ARQ blocks) received from the slave BS 106 A. The BS 106C then generates unfragmented ARQ blocks or MAC SDUs by applying the reassembly function to the fragmented ARQ blocks or MAC SDUs respectively. In case of an ARQ enabled connection  the BS 106C generates MAC SDUs from the ARQ blocks. Then  the BS 106 may optionally apply security function to the MAC SDUs and generates the data packets from the MAC SDUs.

Figures 4A and 4B are schematic representations illustrating Medium Access Control (MAC) layer and Physical (PHY) layer processing performed by a BS in uplink and downlink  in the context of the invention. Typically  when a data packet is received  a BS (e.g.  the BSs 106A-F) performs MAC layer and PHY layer processing on the data packet prior to transmitting the data packet to the network node (e.g.  data gateway  another base station or a mobile station). These functions are performed in a downlink direction by a MAC layer processing module 402 and a PHY layer processing module 404 residing in BSs as illustrated in Figure 4A and in uplink direction by a PHY layer processing module 412 and a MAC layer processing module 414 and residing in BSs as illustrated in Figure 4B. The MAC layer processing module 402 may include a security module 406  an Automatic Repeat Request (ARQ) block generation module 408  an MAC Protocol Data Unit (PDU) generation module 410. The MAC layer processing module 414 may include an MAC PDU generation module 416  an ARQ block generation module 418  and a security module 420. The security modules 406 and 420  and the ARQ block generation modules 408 and 418 are optional and are implemented when the security and ARQ functions are enabled in the BS.

Referring to Figure 4A  in downlink if the security is enabled  the security module 406 generates encrypted MAC Service Data Units (SDUs) from the data packet received from the data gateway 104. The ARQ block generation module 408 generates ARQ blocks from the MAC SDUs. It can be noted that the ARQ function is optional and is not required to be applied on all the MAC SDUs. In other words  the ARQ function is applied only for the MAC SDUs of an ARQ enabled connection. Then  the MAC PDU generation module 410 generates MAC PDUs by applying fragmentation and packing function on the ARQ blocks or MAC SDUs. The MAC PDU generation module 410 may also multiplex ARQ blocks or MAC SDUs from multiple connections in a single MAC PDU. Alternatively  for an ARQ enabled connection  fragmentation and packing function may be applied on the MAC SDUs to generate the ARQ block. In this case  fragmentation and packing function is not applied by the MAC PDU generation module 410. Accordingly  the PHY layer processing module 404 generates one or more PHY PDUs by applying concatenation function on the MAC PDUs received from the MAC layer processing module 402 and processes the one or more PHY PDUs using PHY processing functions (e.g.  coding  modulation  interleaving  etc.).

Referring to Figure 4B  in uplink  the PHY layer processing module 412 performs PHY layer processing functions like demodulation  deinterleaving  decoding etc. on the data packets and generates the PHY PDUs from the data packets. The PHY layer processing module 412 then applies de-concatenation function on the PHY PDUs to generate the MAC PDUs from the PHY PDUs. In case of a non-ARQ enabled connection  the MAC PDU generation module 416 generates the MAC SDUs (fragmented or unfragmented) by applying the unpacking function on the MAC PDU.

In case of an ARQ enabled connection  the MAC PDU generation module 416 generates ARQ blocks (fragmented or unfragmented) by applying the unpacking function on the MAC PDU. Then  the MAC PDU generation module 416 generates unfragmented ARQ blocks or MAC SDUs by applying the reassembly function to the fragmented ARQ blocks or MAC SDUs respectively. In case of an ARQ enabled connection  the ARQ block generation module 408 generates MAC SDUs from the ARQ blocks. The security module 406 optionally applies security to MAC SDUs and generates data packets from the MAC SDUs.

According to the one or more embodiments described above  the MAC layer and/or PHY layer processing of the data packet is performed either completely or in part by a master BS and a slave BS of a cloud cell although the BSs 106A-F are capable of performing MAC layer processing and PHY layer processing on the data packet in entirety. For example  the BS 106C is a master BS in the cloud cell 110A  whereas in the cloud cell 110B  the BS 106C acts as a slave BS while the BS 106E acts as a master BS. In such scenario  the BS 106C can perform partial or complete MAC layer processing and/or complete PHY layer processing of the data packet based on a network node from which the data packet is received and a network node to which the data packet is to be forwarded in the cloud cell.

Figure 5 is a process flowchart 500 illustrating a detailed method of downlink communication of data packets in the cloud cell environment 100 by a BS  according to one embodiment. Consider that  at step 502  data packets are received from a network node by the BS 106C. At step 504  the network node from which the data packets are received is identified by the BS 106C. If the data packets are received from the data gateway 104  at step 506  a network node to which the data packets to be sent is identified.

If the data packets are to be sent to the BS 106A  then at step 508  complete MAC layer processing is performed on the data packets by the BS 106C. At step 510  the MAC PDUs and a logical identifier assigned to the MS 108A are transmitted to the slave BS 106A so that the slave BS 106A performs PHY layer processing on the MAC PDUs and transmits the PHY PDUs to the MS 108A based on the logical identifier (as shown in Figure 6B). If the data packets are to be sent to the MS 108A  then at step 514  complete MAC layer processing and PHY layer processing of the data packets is performed by the BS 106C. At step 516  the PHY PDUs are transmitted to the MS 108A (as shown in Figure 6A).

If at step 504  the network node  from which the MAC PDUs are received  is identified as the master BS 106E  then at step 512  PHY layer processing is performed on the MAC PDUs by the BS 106C. At step 516  the PHY PDUs are transmitted to the MS 108B by the BS 106C (as shown in Figure 6C).

Figure 7 is a process flowchart 700 illustrating a detailed method of uplink communication of data packets in the cloud cell environment 100 by a BS  according to one embodiment. Consider that  at step 702  data packets are received from a network node by the BS 106C. At step 704  the network node from which the data packets are received is identified by the BS 106C. If the data packets are received from the MS 108A or 108B  at step 706  a network node to which the data packets to be sent is identified.

If the data packets are to be sent to the BS 106E  at step 708  PHY layer processing is performed on the data packets by the BS 106C. At step 710  the MAC PDUs are transmitted to the BS 106E so that the master BS 106E performs complete MAC layer processing on the MAC PDUs and transmits the completely processed data packets to the data gateway 104 (as shown in Figure 8B). If the data packets are to be directly sent to the data gateway 104  at step 714  complete MAC layer and PHY layer processing is performed on the data packets by the BS 106C. At step 716  the completely processed data packets are transmitted to the data gateway 104 (as shown in Figure 8A).

If at step 704  the network node  from which the MAC PDUs are received  is identified as the BS 106A  then at step 712  complete MAC layer processing is performed on the MAC PDUs by the BS 106C. At step 716  the completely processed data packets are transmitted to the data gateway 104 (as shown in Figure 8C).

Figure 9 is a process flowchart 900 illustrating a detailed method of downlink communication of data packets in the cloud cell environment 100 by a BS  according to another embodiment. Consider that  at step 902  data packets are received from a network node by the BS 106C. At step 904  the network node from which the data packets are received is identified by the BS 106C. If the data packets are received from the data gateway 104  at step 906  a network node to which the data packets to be sent is identified.

If the data packets are to be sent to the BS 106A  then at step 908  partial MAC layer processing is performed on the data packets by the BS 106C. For example  the MAC layer processing involves generating MAC SDUs  generating ARQ blocks and/or sequence numbering. At step 910  the MAC SDUs/ARQ blocks and/or a logical identifier assigned to the MS 108A are transmitted to the slave BS 106A so that the slave BS 106A performs remaining MAC layer processing on the MAC SDUs or ARQ blocks and then PHY layer processing on the MAC PDUs  and transmits the PHY PDUs to the MS 108A based on the logical identifier (as shown in Figure 10B).

In one embodiment  the BS 106A may buffer the ARQ blocks received from the BS 106C for retransmitting the ARQ blocks to the MS 108A and clear the buffered ARQ blocks based on a predetermined trigger. In one exemplary implementation  the BS 106C may send a control message to the BS 106A indicating successful acknowledgement of ARQ blocks by the MS 108A. The BS 106A may clear the buffered ARQ blocks which are successfully acknowledged via the control message. In another exemplary implementation  the slave BS starts a timer upon receiving the ARQ blocks from the BS 106C and clears the buffered ARQ blocks upon expiry of the timer. The timer may be pre-configured based on time required to schedule  transmit and receive feedback from the MS 108A. In yet another exemplary implementation  the BS 106A may send a poll to the BS 106C to request the status of buffered ARQ blocks. In response  the BS 106C sends the status of buffered ARQ blocks. The BS 106A may clean the buffered ARQ blocks based on the status of the buffered ARQ blocks. In further another exemplary implementation  the BS 106A clears the buffered ARQ blocks when the BS 106A is deleted from the cloud cell 110A.

If the data packets are to be sent to the MS 108A  then at step 914  complete MAC layer processing and PHY layer processing is performed on the data packets by the BS 106C. At step 916  the PHY PDUs are transmitted to the MS 108A (as shown in Figure 10A). If at step 904  the network node  from which the data packets are received  is identified as the master BS 106E  then at step 912  remaining MAC layer processing is performed on the MAC SDUs or ARQ blocks followed by PHY layer processing on the MAC PDUs. For example  the remaining MAC layer processing involves generating MAC PDUs from the MAC SDUs or ARQ blocks. At step 916  the PHY PDUs are transmitted to the MS 108B by the BS 106C (as shown in Figure 10C).

Figure 11 is a process flowchart 1100 illustrating a detailed method of uplink communication of data packets in the cloud cell environment 100 by a BS  according to one embodiment. Consider that  at step 1102  data packets are received from a network node by the BS 106C. At step 1104  the network node from which the data packets are received is identified by the BS 106C. If the data packets are received from the MS 108A or 108B  at step 1106  a network node to which the data packets to be sent is identified.

If the data packets are to be sent to the BS 106E  at step 1108  complete PHY layer processing is performed on the data packets followed by partial MAC layer processing on the MAC PDUs. For example  the partial MAC layer processing involves unpacking the MAC PDUs to generate MAC SDUs. At step 1110  the MAC SDUs are transmitted to the BS 106E so that the master BS 106E performs remaining MAC layer processing on the MAC SDUs and transmits the completely processed data packets to the data gateway 104 (as shown in Figure 12B). If the data packets are to be directly sent to the data gateway 104  at step 1114  complete PHY layer and MAC layer processing is performed on the data packets by the BS 106C. At step 1116  the completely processed data packets are transmitted to the data gateway 104 (as shown in Figure 12A).

If at step 1104  the network node  from which the MAC SDUs are received  is identified as the BS 106A  then at step 1112  remaining MAC layer processing is performed on the MAC SDUs by the BS 106C. For example  said remaining MAC layer processing involves reassembly and reordering of MAC PDUs  generating ARQ blocks and/or generating MAC SDUs. At step 1116  the completely processed data packets are transmitted to the data gateway 104 by the BS 106C (as shown in Figure 12C).

Figure 13 illustrates a block diagram of the BS 106C showing various components for implementing embodiments of the present subject matter. In Figure 13  the BS 106C includes a processor 1302  memory 1304  a read only memory (ROM) 1306  a transceiver 1308  a communication interface 1310  and a bus 1312.

The processor 1302  as used herein  means any type of computational circuit  such as  but not limited to  a microprocessor  a microcontroller  a complex instruction set computing microprocessor  a reduced instruction set computing microprocessor  a very long instruction word microprocessor  an explicitly parallel instruction computing microprocessor  a graphics processor  a digital signal processor  or any other type of processing circuit. The processor 1302 may also include embedded controllers  such as generic or programmable logic devices or arrays  application specific integrated circuits  single-chip computers  smart cards  and the like.

The memory 1304 may be volatile memory and non-volatile memory. The memory 1304 includes a packet manager 1312 for processing and communicating data packets in uplink and downlink  according to the embodiments illustrated in Figures 1 and 12. A variety of computer-readable storage media may be stored in and accessed from the memory elements. Memory elements may include any suitable memory device(s) for storing data and machine-readable instructions such as read only memory  random access memory  erasable programmable read only memory  electrically erasable programmable read only memory  hard drive  removable media drive for handling memory cards  Memory SticksTM  and the like.

Embodiments of the present subject matter may be implemented in conjunction with modules including functions  procedures  data structures  and application programs  for performing tasks  defining abstract data types  or low-level hardware contexts. The packet manager 1312 may be stored in the form of machine-readable instructions on any of the above-mentioned storage media which is then executed by the processor 1302. For example  a computer program may include machine-readable instructions capable of processing and communicating data packets to a network node (e.g.  data gateway  BS  MS)  according to the teachings and herein described embodiments of the present subject matter. The computer program may be included on a storage medium and loaded from the storage medium to a hard drive in the non-volatile memory. Moreover  the components such as the ROM 1306  the transceiver 1308  the communication interface 1310  and the bus 1312 are well known to the person skilled in the art and hence the explanation is thereof omitted.

The present embodiments have been described with reference to specific example embodiments  it will be evident that various modifications and changes may be made to these embodiments without departing from the broader spirit and scope of the various embodiments. Furthermore  the various devices  modules  and the like described herein may be enabled and operated using hardware circuitry  for example  complementary metal oxide semiconductor based logic circuitry  firmware  software and/or any combination of hardware  firmware  and/or software embodied in a machine readable medium. For example  the various electrical structure and methods may be embodied using transistors  logic gates  and electrical circuits  such as application specific integrated circuit.

We claim:

1. A method of a base station for downlink data transmission in a cloud cell  comprising:
identifying a first network node from which at least one data packet intended for a mobile station in a cloud cell is received by a base station  wherein the first network node comprises one of a data gateway and a master base station of the cloud cell;
identifying a second network node in the cloud cell to which the at least one data packet is to be sent if the at least one data packet is received from the data gateway  wherein the second network node comprises one of the mobile station and one of slave base stations of the cloud cell;
performing entire processing of the at least one data packet received from the data gateway and transmitting the entirely processed data packet to the mobile station if the second network node is the mobile station; and
performing partial processing of the at least one data packet received from the data gateway if the second network node is said one of the slave base stations and transmitting the partially processed data packet to said one of the slave base stations so that said one of the slave base stations entirely processes the partially processed data packet and transmits the entirely processed data packet to the mobile station.

2. The method of claim 1  further comprising:
performing entire processing of the at least one data packet if the at least one data packet is received from the master base station  wherein the at least one data packet received from the master base station is a partially processed data packet; and
transmitting the entirely processed data packet to the mobile station.

3. The method of claim 1  wherein performing entire processing of the data packet received from the data gateway comprises:
performing complete Medium Access Control (MAC) layer and Physical (PHY) layer processing of the at least one data packet received from the data gateway.

4. The method of claim 3  wherein performing the complete MAC layer and PHY layer processing of the at least one data packet received from the data gateway comprises:
generating MAC Service Data Units (SDUs) from the at least one data packet received from the data gateway;
generating Automatic Repeat Request (ARQ) blocks from the MAC SDUs;
generating MAC Protocol Data Units (PDUs) by applying fragmentation and packing function on the ARQ blocks or MAC SDUs;
generating one or more PHY PDUs by applying concatenation function on the MAC PDUs; and
processing the one or more PHY PDUs using PHY processing functions.

5. The method of claim 1  wherein performing partial processing of the at least one data packet received from the data gateway comprises:
performing entire Medium Access Control (MAC) layer processing of the at least one data packet received from the data gateway.

6. The method of claim 5  wherein performing the entire MAC layer processing of the at least one data packet received from the data gateway comprises:
generating MAC Service Data Units (SDUs) from the at least one data packet received from the data gateway;
generating Automatic Repeat Request (ARQ) blocks from the MAC SDUs; and
generating MAC Protocol Data Units (PDUs) by applying fragmentation and packing function on the ARQ blocks or MAC SDUs.
.
7. The method of claim 1  wherein performing partial processing of the at least one data packet received from the data gateway comprises:
performing partial Medium Access Control (MAC) layer processing of the at least one data packet received from the data gateway.

8. The method of claim 7  wherein performing the partial MAC layer processing of the at least one data packet received from the data gateway comprises:
generating MAC Service Data Units (SDUs) from the at least one data packet received from the data gateway; and
generating Automatic Repeat Request (ARQ) blocks from the MAC SDUs.

9. The method of claim 2  wherein performing entire processing of the partially processed data packet received from the master base station comprises:
performing remaining Medium Access Control (MAC) layer processing and complete Physical (PHY) layer processing of the partially processed data packet.

10. The method of claim 9  wherein performing the remaining MAC layer processing and complete PHY layer processing of the partially processed data packet comprises:
generating MAC Protocol Data Units (PDUs) by applying fragmentation and packing function on Automatic Repeat Request (ARQ) blocks or MAC Service Data Units (SDUs) in the partially processed data packet;
generating one or more PHY PDUs by applying concatenation function on the MAC PDUs; and
processing the one or more PHY PDUs using PHY processing functions.

11. The method of claim 2  wherein generating the MAC PDUs by applying fragmentation and packing function on the ARQ blocks or the MAC SDUs in the partially processed data packet comprises:
buffering the ARQ blocks received from the master base station in a buffer.

12. The method of claim 11  wherein buffering the ARQ blocks received from the master base station comprises:
receiving a control message indicating ARQ blocks that successfully acknowledged by the mobile station; and
clearing one or more of the buffered ARQ blocks from the buffer based on the control message.

13. The method of claim 11  wherein buffering the ARQ blocks received from the master base station comprises:
clearing one or more of the buffered ARQ blocks from the buffer upon expiry of pre-determined time interval.

14. The method of claim 11  wherein buffering the ARQ blocks received from the master base station comprises:
polling the master base station for status of the buffered ARQ blocks;
receiving a status of the buffered ARQ blocks from the master base station; and
clearing one or more of the buffered ARQ blocks from the buffer based on the status of the buffered ARQ blocks.

15. The method of claim 2  wherein performing entire processing of the partially processed data packet received from the master base station comprises:
performing complete Physical (PHY) layer processing of the partially processed data packet.

16. The method of claim 15  wherein performing the complete PHY layer processing of the partially processed data packet comprises:
generating one or more PHY Protocol Data Units (PDUs) from MAC PDUs received in the partially processed data packet; and
processing the one or more PHY PDUs using PHY processing functions.

17. The method of claim 1  wherein in transmitting the partially processed data packet to said one of the slave base stations comprises:
transmitting the partially processed data packet along with a logical identifier associated with the mobile station to the said one of the slave base station.

18. The method of claim 17  wherein the logical identifier associated with the mobile station is assigned by the master base station.

19. The method of claim 17  wherein the logical identifier associated with the mobile station is assigned by said one of the slave base stations.

20. A base station comprising:
a processor; and
memory coupled to the processor  wherein the memory comprises a packet manager configured for:
identifying a first network node from which at least one data packet intended for a mobile station in a cloud cell is received  wherein the first network node comprises one of a data gateway and a master base station of the cloud cell;
identifying a second network node in the cloud cell to which the at least one data packet is to be sent if the at least one data packet is received from the data gateway  wherein the second network node comprises one of the mobile station and one of slave base stations of the cloud cell;
performing entire processing of the at least one data packet received from the data gateway and transmitting the entirely processed data packet to the mobile station if the second network node is the mobile station; and
performing partial processing of the at least one data packet received from the data gateway if the second network node is said one of the slave base stations and transmitting the partially processed data packet to said one of the slave base stations so that said one of the slave base stations entirely processes the partially processed data packet and transmits the entirely processed data packet to the mobile station.

21. The system of claim 20  wherein the packet manager is configured for:
performing entire processing of the at least one data packet if the at least one data packet is received from the master base station  wherein the at least one data packet received from the master base station is a partially processed data packet; and
transmitting the entirely processed data packet to the mobile station.

22. A method of a base station for uplink data transmission in a cloud cell  comprising:
identifying a first network node in a cloud cell from which at least one data packet intended for an Internet Protocol (IP) network is received by a base station  wherein the first network node comprises one of a mobile station and one of slave base stations;
identifying a second network node to which the at least one data packet is to be sent if the at least one data packet is received from the mobile station  wherein the second network node comprises one of a data gateway and a master base station of the cloud cell;
performing complete processing of the at least one data packet received from the mobile station and transmitting the completely processed data packet to the data gateway if the second network node is the data gateway; and
performing partial processing of the at least one data packet received from the mobile station if the second network node is the master base station and transmitting the partially processed data packet to the master base station so that the master base station entirely processes the partially processed data packet and transmits the entirely processed data packet to the data gateway.

23. The method of claim 22  wherein the second network node is the data gateway if the base station is a master base station of the cloud cell associated with the mobile station from which the at least one data packet is received.

24. The method of claim 22  wherein the second network node is the master base station if the base station is the slave base station of the cloud cell associated with the mobile station from which the at least one data packet is received.

25. The method of claim 22  further comprising:
performing entire processing of the at least one data packet if the at least one data packet is received from said one of the slave base stations  wherein the at least one data packet received from said one of the slave base stations is a partially processed data packet; and
transmitting the entirely processed data packet to the data gateway.

26. The method of claim 22  wherein performing complete processing of the data packet received from the mobile station comprises:
performing complete Medium Access Control (MAC) layer and Physical (PHY) layer processing of the at least one data packet received from the mobile station.

27. The method of claim 26  wherein performing the complete MAC layer and PHY layer processing of the at least one data packet received from the mobile station comprises:
generating PHY Protocol Data Units (PDUs) through applying PHY layer processing functions on the at least one data packet received from the mobile station;
generating MAC PDUs through applying a de-concatenation function to the PHY PDUs;
generating Automatic Repeat Request (ARQ) blocks or MAC Service Data Units (SDUs) through applying unpacking function to the MAC PDUs;
generating unfragmented ARQ blocks or MAC SDUs through applying reassembly function to fragmented ARQ blocks or fragmented MAC SDUs;
generating MAC SDUs from the ARQ blocks; and
forming at least one data packet from the MAC SDUs.

28. The method of claim 22  wherein performing partial processing of the at least one data packet received from the mobile station comprises:
performing Physical (PHY) layer processing of the at least one data packet received from the mobile station.

29. The method of claim 28  wherein performing the PHY layer processing of the at least one data packet received from the mobile station comprises:
generating PHY Protocol Data Units (PDUs) through applying PHY layer processing functions to the at least one data packet received from the mobile station; and
generating MAC PDUs by applying a de-concatenation function to the PHY PDUs.

30. The method of claim 22  wherein performing the partial processing of the at least one data packet received from the mobile station comprises:
performing complete Physical (PHY) layer processing and partial Medium Access Control (MAC) layer on the at least one data packet received from the mobile station.

31. The method of claim 30  wherein performing complete PHY layer processing and partial MAC layer on the at least one data packet received from the mobile station comprises:
generating PHY Protocol Data Units (PDUs) through applying PHY layer processing functions to the at least one data packet received from the mobile station;
generating MAC PDUs by applying a de-concatenation function to the PHY PDUs; and
generating MAC Service Data Units (SDUs) or Automatic Repeat Request (ARQ) blocks through applying unpacking function to the MAC PDUs.

32. The method of claim 25  wherein performing entire processing of the partially processed data packet received from said one of the slave base stations comprises:
performing remaining Medium Access Control (MAC) layer processing of the partially processed data packet received from said one of the slave base stations.

33. The method of claim 32  wherein performing remaining Medium Access Control (MAC) layer processing of the partially processed data packet received from said one of the slave base stations comprises:
generating Automatic Repeat Request (ARQ) blocks through applying reassembly function to fragmented ARQ blocks in the partially processed data packet received from said one of the slave base stations;
generating MAC Service Data Units (SDUs) from the ARQ blocks; and
forming at least one data packet from the MAC SDUs.

34. A base station comprising:
a processor; and
memory coupled to the processor  wherein the memory comprises a packet manager configured for:
identifying a first network node in a cloud cell from which at least one data packet intended for an Internet Protocol (IP) network is received  wherein the first network node comprises one of a mobile station and one of slave base stations;
identifying a second network node to which the at least one data packet is to be sent if the at least one data packet is received from the mobile station  wherein the second network node comprises one of a data gateway and a master base station of the cloud cell;
performing complete processing of the at least one data packet received from the mobile station and transmitting the completely processed data packet to the data gateway if the second network node is the data gateway; and
performing partial processing of the at least one data packet received from the mobile station if the second network node is the master base station and transmitting the partially processed data packet to the master base station so that the master base station entirely processes the partially processed data packet and transmits the entirely processed data packet to the data gateway.

35. The system of claim 34  wherein the packet manager is configured for:
performing entire processing of the at least one data packet if the at least one data packet is received from said one of the slave base stations  wherein the at least one data packet received from said one of the slave base stations is a partially processed data packet; and
transmitting the entirely processed data packet to the data gateway.

Dated this the 13th day of April 2012

Signature

SANTOSH VIKRAM SINGH
Patent Agent
Agent for the applicant