SEAMA:a source encoding assisted multiple access protocol for wireless communication

• US 7,555,011 B2
• Filed: 03/26/2001
• Issued: 06/30/2009
• Est. Priority Date: 02/16/2001
• Status: Expired due to Fees

• Current Assignee: University of Maryland
• Original Assignee: University of Maryland, College Park
• Inventors: Alasti, Mehdi, Farvardin, Nariman
• Primary Examiner(s): NGUYEN, HANH N
• Application Number:
  US10/470,411
• Publication Number:
  US 20040109435A1
• Time in Patent Office: 3,018 Days
• Field of Search: 370/352, 370/389, 370/328, 370/329, 370/336, 370/341, 370/447, 370/395.21, 370/395.4, 370/395.41, 370/468, 370/465, 370/470, 370/471, 370/472, 370/473
• US Class Current: 370/471
• CPC Class Codes: H04L 1/0006 by adapting the transmission format
• CPC Class Codes: H04L 1/0014 by adapting the source coding
• CPC Class Codes: H04W 72/1263 Mapping of traffic onto schedule, e.g. scheduled allocation or multiplexing of flows

Abstract

The invention concerns SEAMA, a source encoding assisted multiple access (MAC) protocol, for integrating voice and data traffic in a wireless network. SEAMA exploits the time variations of the speech coding rate, through statistical multiplexing, to efficiently use the available bandwidth and to increase the link utilization.

Claims

1. A method for integrating voice and data traffic in a wireless network, comprising:

discretizing a wireless transmission at a wireless communication device into frames of fixed length and having an integer number of packets, wherein each such frame is an embedded bit stream comprising;

a voice compartment for carrying digitally encoded voice packets representing a voice portion of the transmission and state information representing a state of a call associated with the transmission, and a data compartment for carrying digital data packets representing a data portion of the transmission, wherein said voice and data compartments are separated from one another by a movable boundary that limits a maximum size of said voice compartment;

for each frame that is to be transmitted from the wireless communication device, adjusting a position of the movable boundary based on the state information and thereby allocate an unused portion of said voice compartment of said frame to said data compartment of said frame; and

generating packets at the wireless communication device for a time interval during which a transmission is made for a current frame such that the packets so generated are transmitted in the next frame, wherein the state information in the voice compartment is transmitted in a header of a first packet of the current frame and contains state information for the state of the call of the next frame.

2. The method of claim 1, wherein each frame comprises a voice set-up compartment comprising mini-slots for adding new calls.

3. The method of claim 1, and further comprising storing at the wireless communication device a scheduling list containing identities and states of all ongoing calls in a current frame.

4. The method of claim 3, and further comprising resolving at the wireless communication device overflow associated with multiple calls by selectively dropping packets from the embedded bit stream of some calls.

5. The method of claim 1, wherein the state information represents the state of the call in terms of a rate used by a voice encoder that digitally encodes voice associated with the call.

6. A method for integrating voice and data traffic in a wireless network, comprising:

discretizing a wireless transmission at a wireless communication device into frames of fixed length and having an integer number of packets, wherein each such frame is an embedded bit stream comprising;

a voice compartment for carrying digitally encoded voice packets representing a voice portion of the transmission and state information representing a state of a call associated with the transmission, and a data compartment for carrying digital data packets representing a data portion of the transmission, wherein said voice and data compartments are separated from one another by a movable boundary that limits a maximum size of said voice compartment, and wherein each frame comprises a voice set-up compartment comprising mini-slots for adding new calls;

for each frame that is to be transmitted from the wireless communication device, adjusting a position of the movable boundary based on the state information and thereby allocate an unused portion of said voice compartment of said frame to said data compartment of said frame that is to be transmitted from the wireless communication device; and

admitting new calls at the wireless communication device using an admission control policy that determines whether the number of calls is less than a network selected maximum number of admissible calls N_max.

7. The method of claim 6, wherein N_max is set to a value such that an average end-to-end distortion per call, E[D], is less than or equal to a network defined threshold, d.

8. The method of claim 6, wherein N_max is set to a value such that a peak-load average distortion, Ē

[D], is less than a network defined threshold, d.

9. A computer readable medium storing instructions that, when executed by the computer in a communication device operating on a wireless network, cause the computer to:

discretize a wireless transmission into frames of fixed length and having an integer number of packets, wherein each such frame is an embedded bit stream comprising;

a voice compartment for carrying digitally encoded voice packets representing a voice portion of the transmission and state information representing a state of a call associated with the transmission, and a data compartment for carrying digital data packets representing a data portion of the transmission, wherein said voice and data compartments are separated from one another by a movable boundary that limits a maximum size of said voice compartment;

for each frame, adjust a position of the movable boundary based on the state information and thereby allocate an unused portion of said voice compartment of said frame to said data compartment of said frame; and

admit new calls using an admission control policy that determines whether the number of calls is less than a network selected maximum number of admissible calls N_max.

10. The computer readable medium of claim 9, and further comprising instructions that, when executed by the computer, generate packets for a time interval during which a transmission is made for a current frame such that the packets so generated are transmitted in the next frame.

11. The computer readable medium of claim 9, wherein said instructions that cause the computer to discretize comprise instructions to generate a voice set-up compartment comprising mini-slots for adding new calls.

12. The computer readable medium of claim 9, wherein the instructions that cause the computer to admit comprise instructions that determine whether the number of calls is less than a value for N_max that is selected such that an average end-to-end distortion per call, E[D], is less than or equal to a network defined threshold, d.

13. The computer readable medium of claim 9, wherein the instructions that cause the computer to admit comprise instructions that determine whether the number of calls is less than a value for N_max that is selected such that a peak-load average distortion, Ē

[D], is less than a network defined threshold, d.

14. The communications network of claim 9, wherein each of the wireless communication devices is configured to store a scheduling list containing identities and states of all ongoing calls in a current frame.

15. The communications network of claim 14, wherein each of the wireless communication devices is configured to resolve overflow associated with multiple calls by selectively dropping packets from the embedded bit stream of some calls.

16. The computer readable medium of claim 9, wherein the instructions that cause the computer to generate the state information comprise instructions that generate the state information in terms of a rate used by a voice encoder that digitally encodes voice associated with the call.

17. A communications network comprising;

a plurality of wireless communication devices, each of is configured to communicate according to a communication protocol to;

discretize a wireless transmission into network frames of fixed length and having an integer number of packets, wherein each such frame is an embedded bit stream comprising;

a voice compartment for carrying digitally encoded voice packets and state information representing a state of a call associated with the transmission, and a data compartment for carrying digital data packets representing a data portion of the transmission, wherein said voice and data compartments are separated from one another by a movable boundary that limits the maximum size of said voice compartment;

for each frame, adjust a position of the movable boundary based on the state information and thereby allocate an unused portion of said voice compartment of said frame to said data compartment of said frame; and

generate packets for a time interval during which a transmission is made for a current frame such that the packets so generated are transmitted in the next frame, wherein the state information of the voice compartment is transmitted in a header of a first packet of the current frame and contains state information for the state of the call of the next frame.

18. The communications network of claim 17, wherein each wireless communication device is configured to generate a voice set-up compartment comprising mini-slots for adding new calls.

19. The communications network of claim 17, wherein each wireless communication device is configured to generate the state information in terms of a rate used by a voice encoder that digitally encodes voice associated with the call.

20. A communications network comprising:

a plurality of wireless communication devices, each of is configured to communicate according to a communication protocol to;

discretize a wireless transmission into network frames of fixed length and having an integer number of packets, wherein each such frame is an embedded bit stream comprising;

a voice compartment for carrying digitally encoded voice packets and state information representing a state of a call associated with the transmission, and a data compartment for carrying digital data packets representing a data portion of the transmission, wherein said voice and data compartments are separated from one another by a movable boundary that limits the maximum size of said voice compartment;

for each frame, adjust a position of the movable boundary based on the state information and thereby allocate an unused portion of said voice compartment of said frame to said data compartment of said frame; and

admit new calls using an admission control policy that determines whether the number of calls is less than a network selected maximum number of admissible calls N_max.

21. The communications network of claim 20, wherein each of the wireless communication devices is configured to determine whether the number of calls is less than a value for N_max that is selected such that an average end-to-end distortion per call, E[D], is less than or equal to a network defined threshold, d.

22. The communications network of claim 20, wherein each of the wireless communication devices is configured to determine whether the number of calls is less than a value for N_max that is selected such that a peak-load average distortion, Ē

[D], is less than a network defined threshold, d.