Radio resource efficient transmission for group communication over LTE eMBMS
A method of supporting group communication over LTE MBMS is provided. A UE first establishes a unicast Evolved Packet Service (EPS) bearer in an LTE network for group communication. The UE belongs to a communication group having a communication group ID. The UE receives access information from the network for monitoring downlink (DL) multicast traffic of the DL group communication based on a multicast decision. The UE is then ready for monitoring a multicast Multimedia Broadcast Multicast Service (MBMS) bearer for receiving the DL multicast traffic. The multicast MBMS bearer is associated with a Temporary Mobile Group Identifier (TMGI), and wherein the TMGI is associated with the communication group ID. The UE de-multiplexes DL traffic received either from the multicast MBMS bearer or from the unicast EPS bearer into a single group communication application.
1. A method comprising:
establishing a unicast Evolved Packet Service (EPS) bearer by a user equipment (UE) in a Long-Term Evolution (LTE) network for receiving downlink (DL) unicast traffic of DL group communication, wherein the UE belongs to a communication group having a group identity (ID);
receiving access information from the network for monitoring a multicast Multimedia Broadcast Multicast Service (MBMS) bearer to receive DL multicast traffic of the DL group communication, wherein the UE receives the DL multicast traffic by monitoring a Physical Downlink Control Channel (PDCCH) scrambled by a group radio identifier (g-RNTI); and
de-multiplexing DL traffic received either from the multicast MBMS bearer or from the unicast EPS bearer and extracting the DL group communication into a group communication application associated with the group ID.
2. The method of claim 1 , wherein the UE receives the DL group communication on the MBMS bearer based on physical layer repetitive transmission to increase robustness.
3. The method of claim 2 , wherein the physical layer repetitive transmission is performed in different frequency domain resources at the same time.
4. The method of claim 1 , wherein the access information comprises MBMS configuration, mapping information between a Temporary Mobile Group Identifier (TMGI) associated with the MBMS bearer and the group ID of the UE, and the group radio identifier (g-RNTI).
5. The method of claim 4 , wherein the UE acquires scheduling information via the PDCCH addressed to the group radio identifier.
6. The method of claim 4 , wherein the group radio identifier is linked to the TMGI, and wherein the group radio identifier is obtained via radio resource control (RRCI) signaling or via a predefined linking rule to the TMGI.
7. The method of claim 1 , wherein the UE and other UEs belonging to the communication group are configured with a common feedback channel for the DL group communication on the MBMS bearer.
8. The method of claim 1 , wherein the UE and other UEs belonging to different communication groups share a common group radio identifier for DL group traffic scheduling.
9. The method of claim 8 , wherein individual TMGIs in MAC sub-headers are used to distinguish the DL group traffic from different groups.
10. The method of claim 1 , wherein uplink (UL) grants for the UE and other UEs from the communication group are scheduled in the same PDCCH.
11. The method of claim 10 , wherein individual Cell Radio Network Temporary Identifiers (C-RNTIs) in MAC sub-headers are used to distinguish the UL grants for the different UEs.
12. A user equipment (UE), comprising:
a configuration module that establishes a unicast Evolved Packet Service (EPS) bearer in a Long-Term Evolution (LTE) network for receiving downlink (DL) unicast traffic of DL group communication, wherein the UE belongs to a communication group having a group (identifier) (ID);
a receiver that receives access information from the network for monitoring a multicast Multimedia Broadcast Multicast Service (MBMS) bearer to receive DL multicast traffic of the DL group communication, wherein the UE receives the DL group communication by monitoring a Physical Downlink Control Channel (PDCCH) scrambled by a group radio identifier (g-RNTI); and
a group communication module that de-multiplexes DL traffic received either from the multicast MBMS bearer or from the unicast EPS bearer and extracting the DL group communication into a group communication application associated with the group ID.
13. The UE of claim 12 , wherein the access information comprises MBMS configuration, mapping information between a Temporary Mobile Group Identifier (TMGI) associated with the MBMS bearer and the group ID of the UE, and the group radio identifier (g-RNTI).
14. The UE of claim 13 , wherein the UE acquires scheduling information via the PDCCH addressed to the group radio identifier.
15. The UE of claim 13 , wherein the group radio identifier is linked to the TMGI, and wherein the group radio identifier is obtained via radio resource control (RRCI signaling or via a predefined linking rule to the TMGI.
16. The UE of claim 12 , wherein the UE and other UEs belonging to the communication group are configured with a common feedback channel for the DL group communication on the MBMS bearer.
17. The UE of claim 12 , wherein the UE and other UEs belonging to different communication groups share a common group radio identifier for DL group traffic scheduling.
18. UE of claim 17 , wherein individual TMGIs in MAC sub-headers are used to distinguish the DL group traffic from different groups.
19. The UE of claim 12 , wherein uplink (UL) grants for the UE and other UEs from the communication group are scheduled in the same PDCCH.
20. The UE of claim 19 , wherein individual Cell Radio Network Temporary Identifiers (C-RNTIs) in MAC sub-headers are used to distinguish the UL grants for the different UEs.