Communication method and apparatus

1 . A communication method, wherein the method comprises:

obtaining a first identity, wherein the first identity comprises at least one of a service identity and a group identity;

determining a first paging occasion based on the first identity, wherein the first paging occasion is used by a first terminal device to receive a first message, and the first message is used to page the first terminal device;

determining, by the first terminal device, a first period; and

in response to the first message being received, initiating random access after the first period, and the first period is determined based on an identity of the first terminal device and a quantity of groups;

wherein

each terminal device of a plurality of terminal devices is part of a corresponding different group, each terminal device of the plurality of terminal devices determines a corresponding different first period of a plurality of first periods;

the first period is in the plurality of first periods;

the first terminal device is in the plurality of terminals; and

the plurality of terminal devices receive the first message on the first paging occasion.

2 . The method according to claim 1 , wherein the method further comprises:

obtaining a discontinuous reception cycle (DRX); and

determining the first paging occasion based on the first identity and the DRX.

3 . The method according to claim 1 , wherein the determining the first paging occasion based on the first identity includes:

determining a first paging frame based on the first identity; and

determining the first paging occasion in the first paging frame based on the first identity.

4 . The method according to claim 3 , wherein the method further comprises obtaining a discontinuous reception cycle (DRX), and wherein the first paging frame satisfies the following formula:

(SFN+PF_offset)mod T =( T div N )*( S _ID mod N ), wherein

SFN is a frame number of the first paging frame, PF_offset is an offset corresponding to the first paging frame, T is the DRX, N is a quantity of paging frames in the DRX, and S_ID is the first identity; and

the first paging occasion satisfies the following formula:

i _ s =floor( S _ID/ N )mod Ns , wherein

i_s is an index value of the first paging occasion, and Ns is a quantity of paging occasions in the first paging frame.

5 . The method according to claim 1 , wherein the first message is scrambled by using a first radio network temporary identity RNTI, wherein the first RNTI and a second RNTI are different RNTIs; and

a second message is scrambled by using the second RNTI, wherein the second message is used to page a second terminal device.

6 . The method according to claim 1 , wherein

the receiving the first message includes receiving at least one of the first identity and a service type; or

the receiving the first message includes receiving an indication that the first terminal device is to receive a third message, wherein the third message includes at least one of the first identity and the service type that are of a first service.

7 . The method according to claim 1 , wherein the obtaining the first identity includes:

sending a request message to a core network device, wherein the request message is used to request the first identity; and

receiving a response message from the core network device, wherein the response message comprises the first identity.

8 . The method according to claim 1 , wherein the first period determined by the first terminal device based on the identity of the first terminal device and the quantity of groups is equal to a following formula:

(( UE _ ID )mod X )* t,

where UE_ID is the identity of the first terminal device, X is the quantity of groups, and t is a second period.

9 . A communication apparatus, wherein the apparatus comprising one or more processors; and a memory, wherein the memory stores a computer program, and in response to executing the computer program stored in the memory, the one or more processors executes operations comprising:

obtaining, a first identity, wherein the first identity includes at least one of a service identity and a group identity;

determining, a first paging occasion based on the first identity, wherein the first paging occasion is used by a first terminal device to receive a first message, and the first message is used to page the first terminal device;

determining, by the communication apparatus, a first period; and

in response to the first message being received, initiating random access after the first period, and the first period is determined based on an identity of the first terminal device and a quantity of groups;

wherein

each terminal device of a plurality of terminal devices is part of a corresponding different group, each terminal device of the plurality of terminal devices determines a corresponding different first period of a plurality of first periods;

the first period is in the plurality of first periods;

the first terminal device is in the plurality of terminals; and

the plurality of terminal devices receive the first message on the first paging occasion.

10 . The apparatus according to claim 9 , wherein the one or more processors executes operations further comprising:

obtaining, a discontinuous reception cycle DRX; and

the determining, the first paging occasion based on the first identity, comprising:

determining the first paging occasion based on the first identity and the DRX.

11 . The apparatus according to claim 9 , wherein the determining, the first paging occasion based on the first identity, includes:

determining, a first paging frame based on the first identity; and

determining, the first paging occasion in the first paging frame based on the first identity.

12 . The apparatus according to claim 11 , wherein the one or more processors executes operations further comprising obtaining, a discontinuous reception cycle DRX, and wherein the first paging frame satisfies a formula according to:

(SFN+PF_offset)mod T =( T div N )*( S _ID mod N ), wherein

SFN is a frame number of the first paging frame, PF_offset is an offset corresponding to the first paging frame, T is the DRX, N is a quantity of paging frames in the DRX, and S_ID is the first identity; and

the first paging occasion satisfies the following formula:

i _ s =floor( S _ID/ N )mod Ns , wherein

i_s is an index value of the first paging occasion, and Ns is a quantity of paging occasions in the first paging frame.

13 . The apparatus according to claim 9 , wherein the one or more processors executes operations further comprising:

scrambling the first message by using a first radio network temporary identity RNTI, wherein the first RNTI and a second RNTI are different RNTIs; and

scrambling a second message is scrambled by using the second RNTI, wherein the second message is used to page a second terminal device.

14 . The apparatus according to claim 9 , wherein

the first message includes at least one of the first identity and a service type; or

the first message indicates that the first terminal device is to receive a third message, wherein the third message includes at least one of the first identity and the service type that are of a first service.

15 . The apparatus according to claim 9 , wherein the one or more processors executes operations further comprising:

sending a request message to a core network device, wherein the request message is used to request the first identity; and receiving a response message from the core network device, wherein the response message includes the first identity.

16 . The apparatus according to claim 9 , wherein the first period determined by the first terminal device based on the identity of the first terminal device and the quantity of groups is equal to a following formula:

(( UE _ ID )mod X )* t,

where UE_ID is the identity of the first terminal device, X is the quantity of groups, and t is a second period.