Group communication signal methods and apparatus

1 . A method of operating an access node servicing a transmission area, the method comprising:

storing, at a first point in time, a first set of group membership information including a first group identifier corresponding to a first group and a first set of end node identifiers corresponding to a first set of end nodes which are members of said first group at said first point in time;

receiving a first set of packets including said first group identifier corresponding to said first group;

determining at least one of a transmission power level, coding rate, and modulation method to be used for transmitting packets to the end nodes which are indicated by said first set of group membership information to be members of said first group, said at least one of a transmission power level, coding rate, and modulation method being determined as a function of information relating to a condition associated with at least one group member; and

transmitting, using said determined at least one of a transmission power level, coding rate, and modulation method a copy of said first set of packets, said transmitted copy of the first set of packets being directed to a plurality of said group members.

2 . The multicast communications method of claim 1 , wherein said determined at least one of a transmission power level, coding rate, and modulation method is a power level which is lower than a power level which would be required to reach all end nodes in said serviced transmission area but is sufficient to reach all the end nodes in said first group.

3 . The method of claim 2 ,

wherein said condition is a channel condition;

wherein said transmission area is a cell; and

wherein said determined transmission power level is insufficient to reach all end nodes in said serviced transmission area at a given coding rate but is sufficient to reach all end nodes in said first group.

4 . The method of claim 2 ,

wherein said condition is a channel condition; and

wherein said transmission area is a sector.

5 . The method of claim 4 , wherein said condition is a location condition.

6 . The multicast communications method of claim 1 , wherein said determined at least one of a transmission power level, coding rate, and modulation method is a power level and wherein said determining step is dynamically performed to adjust the transmission power level as a function of a channel condition associated with the end node in said first group having the worst estimated channel conditions over a period of time.

7 . The multicast communications method of claim 1 , wherein said determined at least one of a transmission power level, coding rate, and modulation method is a coding rate which is higher than a lower coding rate which would be required to reach all end nodes in said serviced transmission area at a given transmission power level but is sufficient to reach all end nodes in said first group.

8 . The multicast communications method of claim 1 , further comprising:

storing, at a second point in time, updated group membership information, said updated group membership information including the first group identifier corresponding to the first group and a second set of end node identifiers corresponding to a second set of end nodes which are members of said first group at said second point in time;

receiving a second set of packets including said first group identifier corresponding to said first group;

determining at least one of a transmission power level and coding rate to be used for transmitting a copy of said second set of packets to the end nodes which are indicated by said updated set of group membership information to be members of said first group, said at least one of a transmission power level and coding rate being determined as a function of information relating to a condition associated with at least one group member; and

transmitting a copy of said second set of packets to the end nodes indicated by said updated set of group membership information to be members of said first group.

9 . The method of claim 8 , wherein the first group includes different end node at said first and second times.

10 . The method of claim 8 , wherein the first group has the same end nodes in said first group at said first and second times but there has been a change in the channel condition associated with the at least one group member, said at least one group member being the end node in said first group with the worst channel conditions.

11 . The method of claim 8 , wherein the power level used to transmit said copy of said second set of packets is different from the power level used to transmit said copy of said first set of packets.

12 . The multicast communications method of claim 8 ,

wherein said determined at least one of a transmission power level and coding rate to be used for transmitting a copy of said second set of packets is a power level; and

wherein said determining step is performed to select the transmission power level so that the transmitted copy of said second set of packets will be transmitted with sufficient power to reach each of the end nodes indicated to be members of said first group by said updated set of group membership information.

13 . The multicast communications method of claim 11 ,

wherein said determined at least one of a transmission power level and coding rate to be used for transmitting a copy of said second set of packets is a coding rate; and

and wherein said determining step is performed to select the coding rate so that the transmitted copy of said second set of packets will be transmitted with a coding rate sufficient to reach each of the end nodes indicated to be members of said first group by said updated set of group membership information, the determined coding rate being higher than a lower coding rate which would be required to reach all end nodes in said serviced transmission area given a transmission power level which is used to transmit said copy of said second set of packets.

14 . The method of claim 1 , further comprising:

storing, at said first point in time, a second set of group membership information including a second group identifier corresponding to a second group and a second set of end node identifiers corresponding to a second set of end nodes which are members of said second group at said first point in time;

receiving a second set of packets including said second group identifier corresponding to said second group;

determining at least one of a transmission power level and coding rate to be used for transmitting packets to the end nodes which are indicated by said second set of group membership information to be members of said second group, said at least one of a transmission power level and coding rate being determined as a function of information relating to a condition associated with at least one member of said second group; and

transmitting a copy of said second set of packets using said determined at least one of a transmission power level and coding rate, said transmitted copy of the second set of packets being directed to a plurality of said group members.

15 . An apparatus for servicing a transmission area, comprising:

memory including, at a first point in time, a first stored set of group membership information including a first group identifier corresponding to a first group and a first set of end node identifiers corresponding to a first set of end nodes which are members of said first group at said first point in time;

a receiver for receiving a first set of packets including said first group identifier corresponding to said first group;

a transmission control module for determining at least one of a transmission power level and coding rate to be used for transmitting packets to the end nodes which are indicated by said first set of group membership information to be members of said first group, said at least one of a transmission power level and coding rate being determined as a function of information relating to a condition associated with at least one group member; and

a transmitter coupled to said transmission control module for transmitting, using said determined at least one of a transmission power level and coding rate, a copy of said first set of packets, said transmitted copy of the first set of packets being directed to a plurality of said group members.

16 . The apparatus of claim 15 , wherein said determined at least one of a transmission power level and coding rate is a power level which is lower than a power level which would be required to reach all end nodes in said serviced transmission area but is sufficient to reach all the end nodes in said first group.

17 . The apparatus of claim 16 ,

wherein said condition is a channel condition; and

wherein said transmission area is a cell.

18 . The apparatus of claim 16 ,

wherein said condition is a channel condition; and

wherein said transmission area is a sector.

19 . The apparatus of claim 16 , wherein said condition is a location condition.

20 . The apparatus of claim 15 , wherein said determined at least one of a transmission power level and coding rate is a power level and wherein said transmission control module includes:

means for adjusting the determined transmission power level in response to changes in channel condition information, as a channel condition associated with the end node in said first group having the worst channel conditions changes over time.

21 . The apparatus of claim 15 , wherein said determined at least one of a transmission power level and coding rate is a coding rate which is higher than a lower coding rate which would be required to reach all end nodes in said serviced transmission area given a transmission power level which is used but is sufficient to reach all end nodes in said first group.

22 . The apparatus of claim 21 , further comprising:

a group membership control module for updating group membership information;

within said memory, at a second point in time, a stored set of updated group membership information, said updated group membership information including the first group identifier corresponding to the first group and a second set of end node identifiers corresponding to a second set of end nodes which are members of said first group at said second point in time, the first group having different end node membership at said first and second times;

wherein said receiver includes means for receiving a second set of packets including said first group identifier corresponding to said first group; and

wherein said transmission control module includes means for determining at least one of a transmission power level and coding rate to be used for transmitting a copy of said second set of packets to the end nodes which are indicated by said updated set of group membership information to be members of said first group, said at least one of a transmission power level and coding rate being determined as a function of information relating to a condition associated with at least one group member.

23 . The apparatus of claim 22 , wherein the power level determined to be used to transmit said copy of said second set of packets is different from the power level used to transmit said copy of said first set of packets.

24 . The apparatus of claim 22 ,

wherein said determined at least one of a transmission power level and coding rate to be used for transmitting a copy of said second set of packets is a power level; and

wherein said transmission control module includes:

means for selecting the transmission power level so that the transmitted copy of said second set of packets will be transmitted with sufficient power to reach each of the end nodes indicated to be members of said first group by said updated set of group membership information.

25 . The apparatus of claim 23 ,

wherein said determined at least one of a transmission power level and coding rate to be used for transmitting a copy of said second set of packets is a coding rate;

and wherein said transmission control module includes:

means for selecting the coding rate so that the transmitted copy of said second set of packets will be transmitted with a coding rate sufficient to reach each of the end nodes indicated to be members of said first group by said updated set of group membership information, the determined coding rate being higher than a lower coding rate which would be required to reach all end nodes in said serviced transmission area given a transmission power level which is used to transmit said copy of said second set of packets.

26 . The apparatus of claim 15 ,

wherein at said first point in time said memory further includes a stored second set of group membership information including a second group identifier corresponding to a second group and a second set of end node identifiers corresponding to a second set of end nodes which are members of said second group at said first point in time; and

wherein said transmission control module further includes:

means for determining at least one of a transmission power level and coding rate to be used for transmitting packets to the end nodes which are indicated by said second set of group membership information to be members of said second group, said at least one of a transmission power level and coding rate being determined as a function of information relating to a condition associated with at least one member of said second group.