Demand assignment system and method for mobile users in a community of interest

• US 5,506,848 A
• Filed: 06/22/1994
• Issued: 04/09/1996
• Est. Priority Date: 06/22/1994
• Status: Expired due to Term

• Current Assignee: AT&T Corporation (AT&T, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Drakopoulos, Elias, Gerakoulis, Diakoumis P.
• Primary Examiner(s): Marcelo, Melvin
• Assistant Examiner(s): VU, HUY DUY
• Application Number:
  US08/263,697
• Time in Patent Office: 657 Days
• Field of Search: 370/95.1, 370/95.2, 370/95.3, 370/97, 370/77, 370/78, 370/79, 370/80, 370/81, 370/85.7, 370/94.1, 370/94.2, 370/84, 455/11.1, 455/13.1, 455/16
• US Class Current: 370/336
• CPC Class Codes: H04W 28/26 Resource reservation
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal

Abstract

A procedure for assigning time slots to mobile users in a wireless communication system supporting wireless communication applications where both end users of a communication link are mobile is discussed. The procedure operates by receiving time slot reservation requests from the mobile users during a first frame, wherein each of the time slot reservation requests comprises information identifying a source end user and a destination end user. During the first frame, a voice traffic matrix and a data traffic matrix are generated by using the time slot reservation requests. The voice traffic matrix comprises source end user information and destination end user information for all active voice calls, and the data traffic matrix comprises source end user and destination end user information for all pending data packets. Also during the first frame, time slot assignment information is generated based on the voice traffic matrix and the data traffic matrix. This time slot assignment information is then transmitted to the mobile users. The mobile users transmit and receive voice packets and data packets during time slots of a second frame as specified by the time slot assignment information.

Claims

1. A method of assigning time slots to mobile users in a wireless communication system supporting wireless communication applications where both end users of a communication link are mobile, comprising the steps of:

(1) receiving time slot reservation requests from the mobile users during a first frame, each of said time slot reservation requests comprising information identifying a source end user and a destination end user;

(2) generating during said first frame a voice traffic matrix and a data traffic matrix by using said time slot reservation requests, said voice traffic matrix comprising source end user information and destination end user information for all active voice calls, and said data traffic matrix comprising source end user and destination end user information for all pending data packets;

wherein step (2) comprises the steps of,

(a) identifying which of said time slot reservation requests, if any, represent new voice call requests, and

(b) determining whether to accept said identified new voice call requests, said identified new voice call requests which are accepted representing a subset of said active voice calls, and said identified new voice call requests which are not accepted representing blocked voice calls;

(3) generating, during said first frame, time slot assignment information based on said voice traffic matrix and said data traffic matrix; and

(4) transmitting, during said first frame, said time slot assignment information to the mobile users;

wherein the mobile users transmit and receive voice packets and data packets during time slots of a second frame as specified by said time slot assignment information.

2. The method of claim 1, in which L_c time slots in each frame are reserved for voice service, wherein step (2)(b) comprises the step of accepting one of said identified new voice call requests when conditions A and B are satisfied:

##EQU26## where T_o represents a matrix of said active voice calls, and t_ij (T_o) represents an entry at row i and column j of matrix T_o.

3. The method of claim 1, wherein step (3) comprises the step of:

assigning a time slot in each frame to each active voice call represented in said voice traffic matrix, such that voice service is guaranteed.

4. The method of claim 1, wherein step (3) comprises:

(a) determining whether sufficient capacity exists to transmit all of said pending data packets represented in said data traffic matrix during said second frame; and

(b) if it is determined in step (3)(a) that sufficient capacity does not exist, then extracting dam packet information from said data traffic matrix until said data traffic matrix only contains data traffic information for data packets that can be transmitted during said second frame.

5. The method of claim 4, in which each frame includes L time slots, wherein step (3)(a) comprises the step of:

determining that sufficient capacity does not exist if L is less than a sum of said active voice calls and said pending data packets.

6. The method of claim 1, in which each frame includes L time slots, wherein step (3) comprises the steps of:

(a) scheduling for transmission in L_c of said L time slots said active voice calls represented in said voice traffic matrix;

(b) identifying any of said L_c time slots not being used for voice service; and

(c) scheduling for transmission in L_p of said L time slots and said identified L_c time slots said pending data packets represented in said data traffic matrix,

wherein the sum of said L_c and L_p time slots equals said L time slots.

7. The method of claim 6, wherein step (4) comprises the steps of:

(a) identifying any of said pending data packets not scheduled for transmission in said L_p time slots and said identified L_c time slots; and

(b) causing the mobile users to buffer said identified data packets.

8. A method of assigning time slots to mobile users in a wireless communication System supporting wireless communication applications where both end users of a communication link are mobile, comprising the steps of:

(1) receiving time slot reservation requests from the mobile users during a first frame, each of said time slot reservation requests comprising information identifying a source end user and a destination end user;

(2) generating during said first frame a voice traffic matrix and a data traffic matrix by using said time slot reservation requests, said voice traffic matrix comprising source end user information and destination end user information for all active voice calls, and said data traffic matrix comprising source end user and destination end user information for all pending data packets;

(3) generating, during said first frame, time slot assignment information based on said voice traffic matrix and said data traffic matrix,

wherein step (3) comprises the step of employing a predetermined scheduling algorithm to generate said time slot assignment information, said predetermined scheduling algorithm supporting fixed length frames, integrated voice and data service, guaranteed voice service, buffering of data packets by the mobile users, and a moveable boundary approach wherein L_c time slots in each frame are reserved for voice service, L_p time slots in each frame are reserved for data service, and any of said L_c time slots not used for voice service may be used for data service; and

(4) transmitting, during said first frame, said time slot assignment information to the mobile users;

wherein the mobile users transmit and receive voice packets and data packets during time slots of a second frame as specified by said time slot assignment information.

9. A wireless communication system, comprising:

a radio exchange node, REN;

a plurality of RF-distribution points, RDPs, each including antenna equipment to receive time slot reservation requests from mobile users, and to forward said time slot reservation requests to said REN;

said REN comprising;

a switch;

a scheduling unit to receive said time slot reservation requests from said RDPs during a first frame, to generate during said first frame a voice traffic matrix and a data traffic matrix by using said time slot reservation requests and a fixed frame, moveable boundary approach wherein L_c time slots in each frame are reserved for voice service, L_p time slots in each frame are reserved for data service, and any of said L_c time slots not used for voice service may be used for data service, and said voice traffic matrix comprising source and destination end user information for all active voice calls, and said data traffic matrix comprising source and destination end user information for all pending data packets, and to generate during said first frame time slot assignment information based on said voice traffic matrix and said data traffic matrix; and

a control unit to transmit, during said first frame, said time slot assignment information to said mobile users via said RDPs, and to control said switch such that connectivity is provided between said mobile users during a second frame in accordance with said time slot assignment information.

10. A system of assigning time slots to mobile users in a wireless communication system supporting wireless communication applications where both end users of a communication link are mobile, comprising:

receiving means for receiving time slot reservation requests from the mobile users during a first frame, each of said time slot reservation requests comprising information identifying a source end user and a destination end user;

matrix generating means for generating during said first frame a voice traffic matrix and a data traffic matrix by using said time slot reservation requests, said voice traffic matrix comprising source end user information and destination end user information for all active voice calls, and said data traffic matrix comprising source end user and destination end user information for all pending data packets;

wherein said matrix generating means comprises,

means for identifying which of said time slot reservation requests, if any, represent new voice call requests, and

new call accepting means for determining whether to accept said identified new voice call requests, said identified new voice call requests which are accepted representing a subset of said active voice calls, and said identified new voice call requests which are not accepted representing blocked voice calls;

time slot assignment information generating means for generating, during said first frame, time slot assignment information based on said voice traffic matrix and said data traffic matrix; and

transmitting means for transmitting, during said first frame, said time slot assignment information to the mobile users;

wherein the mobile users transmit and receive voice packets and data packets during time slots of a second frame as specified by said time slot assignment information.

11. The system of claim 10, in which L_c time slots in each frame are reserved for voice service, wherein said new call accepting means comprises means for accepting one of said identified new voice call requests when conditions A and B are satisfied:

##EQU27## where T_o represents a matrix of said active voice calls, and t_ij (T_o) represents an entry at row i and column j of matrix T_o.

12. The system of claim 10, wherein said time slot assignment information generating means comprises:

means for assigning a time slot in each frame to each active voice call represented in said voice traffic matrix, such that voice service is guaranteed.

13. The system of claim, 10, wherein said time slot assignment information generating means comprises:

sufficient capacity determining means for determining whether sufficient capacity exists to transmit all of said pending data packets represented in said data traffic matrix during said second frame; and

means for extracting data packet information from said data traffic matrix until said data traffic matrix only contains data traffic information for data packets that can be transmitted during said second frame if it is determined that sufficient capacity does not exist.

14. The system of claim 13, in which each frame includes L time slots, wherein said sufficient capacity determining means comprises:

means for determining that sufficient capacity does not exist if L is less than a sum of said active voice calls and said pending data packets.

15. The system of claim 10, in which each frame includes L time slots, wherein said time slot assignment information generating means comprises:

means for scheduling for transmission in L_c of said L time slots said active voice calls represented in said voice traffic matrix;

means for identifying any of said L_c, time slots not being used for voice service; and

means for scheduling for transmission in L_p of said L time slots and said identified L_c time slots said pending data packets represented in said data traffic matrix,

wherein the sum of said L_c land L_p time slots equals said L time slots.

16. The system of claim, 15, wherein said transmitting means comprises:

means for identifying any of said pending data packets not scheduled for transmission in said L_p time slots and said identified L_c time slots; and

means for causing the mobile users to buffer said identified data packets.

17. A system of assigning time slots to mobile users in a wireless communication system supporting wireless communication applications where both end users of a communication link are mobile, comprising:

receiving means for receiving time slot reservation requests from the mobile users during a first frame, each of staid time slot reservation requests comprising information identifying a source end user and a destination end user;

matrix generating means for generating during said first frame a voice traffic matrix and a data traffic matrix by using said time slot reservation requests, said voice traffic matrix comprising source end user information and destination end user information for all active voice calls, and said data traffic matrix comprising source end user and destination end user information for all pending data packets;

time slot assignment information generating means for generating, during said first frame, time slot assignment information based on said voice traffic matrix and said dam traffic matrix,

wherein said time slot assignment information generating means comprises,

means for employing a predetermined scheduling algorithm to generate said time slot assignment information, said predetermined scheduling algorithm supporting fixed length frames, integrated voice and data service, guaranteed voice service, buffering of data packets by the mobile users, and a moveable boundary approach wherein L_c time slots in each frame are reserved for voice service, L_p time slots in each frame are reserved for data service, and any of said L_c time slots not used for voice service may be used for data service; and

transmitting means for transmitting, during said first frame, said time slot assignment information to the mobile users;

wherein the mobile users transmit and receive voice packets and data packets during time slots of a second frame as specified by said time slot assignment information.