Transmission parameter control device

• US 20070030821A1
• Filed: 09/10/2003
• Published: 02/08/2007
• Est. Priority Date: 09/10/2003
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Hatakeyama, Shinya, Miyagawa, Yasushi, Iwamura, Naoto, Yamaguchi, Seiichi
• Granted Patent: US 7,463,578 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/1867 Arrangements specially adapted for the transmitter end
• CPC Class Codes: H04L 1/205 jitter monitoring
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/2416 Real-time traffic
• CPC Class Codes: H04L 47/2458 Modification of priorities while in transit
• CPC Class Codes: H04L 47/25 with rate being modified by the source upon detecting a change of network conditions
• CPC Class Codes: H04L 47/283 in response to processing delays, e.g. caused by jitter or round trip time [RTT]
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/65 Network streaming protocols, e.g. real-time transport protocol [RTP] or real-time control protocol [RTCP]
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04W 28/0236 radio quality, e.g. interference, losses or delay
• CPC Class Codes: H04W 28/10 Flow control between communication endpoints
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]

Abstract

An object of the present invention is to provide a transmission parameter control apparatus that can improve transmission quality of real-time media in a transmission route that includes a wireless section in at least a part of the transmission route. According to the present invention, a transmission parameter control apparatus 200 that is connected to a terminal 104 via a network 102 and that is connected to a mobile terminal 108 via a wireless link, is provided. The apparatus includes: an obtaining part 210 for obtaining a quality parameter indicating transmission quality corresponding to the wireless link from signals of downlink and uplink transmission routes; and an adjustment part 220 for adjusting a value of a transmission parameter determining a transmission scheme in the wireless link according to the quality parameter.

Claims

1. A transmission parameter control apparatus that is connected to a terminal via a network and that is connected to a mobile terminal via a wireless link, comprising:

an obtaining part for obtaining a quality parameter indicating transmission quality corresponding to the wireless link from signals of downlink and uplink transmission routes; and

an adjustment part for adjusting a value of a transmission parameter that determines a transmission scheme in the wireless link according to the quality parameter.

2. The transmission parameter control apparatus as claimed in claim 1, comprising:

an extraction part for extracting a time stamp on a voice or video signal from a signal on a downlink transmission route to the mobile terminal or from a signal on an uplink transmission route to the fixed terminal.

3. The transmission parameter control apparatus as claimed in claim 1, wherein the obtaining part determines quality parameter obtained from the signal of the downlink transmission route to be first quality parameter between the terminal and the transmission parameter control apparatus, and derives the quality parameter corresponding to the wireless link from a difference between the first quality parameter and a second quality parameter obtained from the signal of the uplink transmission route.

4. The transmission parameter control apparatus as claimed in claim 1, wherein the quality parameter is represented by a jitter indicating fluctuations of packet transfer time, a packet discard ratio or a packet delay time.

5. The transmission parameter control apparatus as claimed in claim 1, wherein the transmission parameter that determines the transmission scheme of the wireless link is represented by a number of packet retransmissions, a transmission priority of packet, or an error correction level.

6. The transmission parameter control apparatus as claimed in claim 4, wherein the adjustment part performs adjustment such that a number of packet retransmissions decreases or increases according to size of the jitter.

7. The transmission parameter control apparatus as claimed in claim 4, wherein the adjustment part performs adjustment such that a transmission priority of packet is heightened or lowered according to size of the jitter.

8. The transmission parameter control apparatus as claimed in claim 4, wherein the adjustment part performs adjustment such that a number of packet retransmissions increases or decreases according to size of the packet discard ratio.

9. The transmission parameter control apparatus as claimed in claim 4, wherein the adjustment part performs adjustment such that an error correction level is heightened or lowered according to size of the packet discard ratio.

10. The transmission parameter control apparatus as claimed in claim 4, wherein the adjustment part performs adjustment such that a number of packet retransmissions decreases or increases according to size of the delay time.

11. The transmission parameter control apparatus as claimed in claim 4, wherein the adjustment part performs adjustment such that an error correction level is lowered or heightened according to size of the delay time.

12. The transmission parameter control apparatus as claimed in claim 4, wherein the adjustment part performs adjustment such that a transmission priority of packet is heightened or lowered according to size of the delay time.