Enhanced VoIP media flow quality by adapting speech encoding based on selected modulation and coding scheme (MCS)

• US 8,289,952 B2
• Filed: 02/03/2006
• Issued: 10/16/2012
• Est. Priority Date: 05/25/2005
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Larsson, Anders, Bladsjö, David, Cerwall, Patrik, Bäckström, Martin Lars
• Primary Examiner(s): Nawaz, Asad
• Assistant Examiner(s): KASSIM, KHALED M
• Application Number:
  US11/346,565
• Publication Number:
  US 20060268837A1
• Time in Patent Office: 2,447 Days
• Field of Search: 370352-356, 370/328, 370/528, 375/264, 375/267, 375/260
• US Class Current: 370/352
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0014 by adapting the source coding
• CPC Class Codes: H04L 1/0083 Formatting with frames or packets; Protocol or part of protocol for error control
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/38 by adapting coding or compression rate
• CPC Class Codes: H04L 65/1016 IP multimedia subsystem [IMS]
• CPC Class Codes: H04L 65/70 Media network packetisation
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04W 28/0231 based on communication conditions dynamic wireless traffic scheduling definition based on channel quality criteria H04W72/54
• CPC Class Codes: H04W 28/12 using signalling between network elements
• CPC Class Codes: H04W 72/54 based on quality criteria
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]

Abstract

A voice-over-IP (VoIP) connection is established over a radio interface with a mobile radio station. A current radio condition for the VoIP connection is determined, and from that, a modulation and coding scheme (MCS) for a portion of the VoIP connection. A VoIP voice encoding mode for a portion of the VoIP connection is selected based on the determined modulation coding scheme. VoIP voice is then encoded into a number of VoIP encoded frames using the selected VoIP voice encoding mode which has an associated bit rate. An optimal number of VoIP encoded frames is included in a VoIP packet for transport over the VoIP connection given the selected voice encoding mode and the selected MCS. Other adjustments may be made to ensure robustness of the VoIP connection and/or to maximize capacity.

Claims

1. A method for use with a voice-over-IP (VoIP) connection established over a radio interface with a mobile radio station, comprising:

determining a current radio condition associated with the VoIP connection;

determining a modulation and coding scheme (MCS) for a portion of VoIP information to be communicated over the VoIP connection based on the determined current radio condition;

selecting a VoIP voice encoding mode for a portion of the VoIP connection based at least in part on the determined modulation coding scheme, the VoIP voice encoding mode having an associated bit rate;

encoding VoIP voice into a variable number of VoIP encoded frames using the selected VoIP voice encoding mode, wherein the variable number of VoIP encoded frames depends on the determined MCS;

including the number of VoIP encoded frames in a VoIP packet for transport over the VoIP connection;

and wherein the variable number of VoIP encoded frames is an optimal number to increase the amount of VoIP bits included in a radio block transmitted over the radio interface.

2. The method in claim 1, further comprising:

varying the variable number of VoIP encoded frames when a different MCS is determined for the VoIP connection.

3. The method in claim 1, further comprising:

selecting a VoIP voice encoding mode at a lower data rate than what the determined MCS can support.

4. The method in claim 1, further comprising:

selecting an MCS lower than the determined MCS for the current radio condition.

5. The method in claim 1, wherein the method is for use in a GPRS or EDGE type system, radio channel resources for supporting connections include time slots, and the VoIP voice encoding mode is an adaptive multi-rate (AMR) coder/decoder (codec).

6. The method in claim 5, further comprising:

determining a number of timeslots to use in transmitting the VoIP packet.

7. The method in claim 6, further comprising:

using one more time slot that the determined number to transmit the VoIP packet.

8. The method in claim 6, further comprising:

forming a radio transmission block using the VoIP packet;

channel encoding and modulating the radio transmission block using the determined MCS; and

transmitting the channel encoded and modulated radio transmission block over the radio interface using the determined number of time slots.

9. The method in claim 8, wherein the radio transmission block is a fixed size, the method further comprising:

adjusting the number of VoIP encoded frames included in the VoIP packet to fill in the radio transmission block.

10. The method in claim 8, further comprising:

selecting one or more of the following to increase robustness of the VoIP connection;

lower the MCS, lower the rate of the VoIP voice coder, increase the number of time slots, or adjust the number of VoIP voice coder frames per IP packet to fill in the radio block for the selected MCS and the selected VoIP voice coder rate.

11. The method in claim 8, further comprising:

detecting a change in radio conditions for the VoIP connection; and

selecting one or more of the following if the change is an improved radio condition;

increase the MCS, increase the rate of the VoIP voice coder, decrease the number of time slots, or adjust the number of VoIP voice coder frames per IP packet to fill in the radio block for the selected MCS and the selected VoIP voice coder rate.

12. The method in claim 1 implemented in the mobile station or in an Internet Protocol Multimedia Subsystem (IMS) node.

13. An apparatus for use in a mobile node for supporting a voice-over-IP (VoIP) connection established over a radio interface via a radio access network, comprising:

a modulation and coding scheme (MCS) selector for selecting a channel encoding scheme and the modulation scheme use for a portion of VoIP voice information to be transmitted over the VoIP connection based on a determined current radio condition associated with the VoIP connection;

a VoIP voice encoder that includes a processing system that includes at least one processor, the processing system configured to (1) select a voice encoding mode for the portion of VoIP voice information based at least in part on the selected MCS, the VoIP voice encoding mode having an associated bit rate, and (2) encode the VoIP voice information into a variable number of VoIP encoded frames using the selected VoIP voice encoding mode, wherein the variable number of VoIP encoded frames depends on the selected MCS;

a VoIP packetizer for including the number of VoIP encoded frames in a VoIP packet for transport over the VoIP connection;

and wherein the variable number of VoIP encoded frames is an optimal number to increase an amount of VoIP bits included in a radio block transmitted over the radio interface by the mobile node.

14. The apparatus in claim 13, wherein the VoIP voice encoder is further configured to vary the variable number of VoIP encoded frames when a different MCS is determined for the VoIP connection.

15. The apparatus in claim 13, wherein the VoIP voice encoder is further configured to select a VoIP voice encoding mode having a lower bit rate than what the determined MCS can support.

16. The apparatus in claim 13, wherein the MCS selector is configured to select an MCS lower than the MCS determined for the current radio condition.

17. The apparatus in claim 13, wherein the apparatus is configured for use in a GPRS type system where radio channel resources for supporting the VoIP connection include time slots and the VoIP voice encoder is an adaptive multi-rate (AMR) coder/decoder (codec).

18. The apparatus in claim 17, further comprising:

circuitry for determining a number of timeslots to use in transmitting the VoIP packet.

19. The apparatus in claim 18, further comprising:

circuitry configured to form a radio transmission block using the VoIP packet;

a channel encoder for channel encoding information based on the selected channel encoding scheme;

a modulator for modulating channel encoded information from the channel encoder based on the selected modulation scheme; and

radio transceiving circuitry configured to transmit the modulated information over the radio interface using one more time slot than the determined number of time slots.

20. The apparatus in claim 19, wherein the radio transmission block is a fixed size, and wherein the VoIP voice encoder is configured to adjust the number of VoIP encoded frames included in the VoIP packet to fill in the radio transmission block.

21. The apparatus in claim 19, further comprising:

control circuitry configured to select one or more of the following to increase robustness of the VoIP connection;

lower the MCS, lower the rate of the VoIP voice coder, increase the number of time slots, or adjust the number of VoIP voice coder frames per IP packet to fill in the radio block for the selected MCS and the selected VoIP voice coder rate.

22. The apparatus in claim 19, further comprising:

control circuitry configured to select one or more of the following when the current radio condition improves;

increase the MCS, increase the rate of the VoIP voice coder, decrease the number of time slots, or adjust the number of VoIP voice coder frames per IP packet to fill in the radio block for the selected MCS and the selected VoIP voice coder rate.