Video-Cooperative Design for Ad Hoc Networks

Abstract

As wireless channels in ad hoc networks are capacity-limited, deployment of video applications is a challenging task. This study investigates intermediate nodes on relaying real-time video packets. We propose a video-cooperative framework in which each relaying node transiently retains packets so that they can be appropriately selected to forward when congestion occurs. In the framework, retransmission can be made from intermediate nodes instead of the very sender. This obviously shortens the retransmission round, resulting in higher end-toend successful rate and lower cumulative power consumption. These nodes can also detect and drop packets that have missed deadline. Once rejecting an important packet, a video-cooperative node may also notify other nodes to jointly destroy its dependent packets (that are definitely useless). This mechanism does save both bandwidth and energy for useful packets. Experimental results collected from a testbed demonstrate that our proposed framework is feasible and efficient.

Delay-constrained adaptive early drop for real-time video delivery over IEEE 802.11 wireless networks

“…To provide interactive services, a video frame should be played within 400msafter it is encodedaccording to ITU-T [6]. Another approach [7] drops a video packet which exceeds time-tolive in an intermediate router, but it requires the cache for the packet retransmission on every node. Besides, the receiver should inform which packets it does not receive to everyupstream node.…”

Efficient delivery of monitoring data in networked fishing boats

“…A practical solution is to share walkie-talkie's radio channels for transmitting the data [1] [2][3]. However, deployment of such ubiquitous systems obviously faces numerous technical challenges due to node mobility and channel errors [4][5] [6] [7]. Missed or altered data may lead to wrong decisions by fishermen and/or coastal mission teams.…”

“…It is therefore practical to augment algorithms for smarter processing and caching packets at ending and intermediate nodes in exchange for communication efficiency. At the same time, introduction of packet retransmission for enhancing data reliability [4][8] [9] shall also be realistic. Secondly, transport protocols targeted end-to-end reliability [5][6] [10] normally let each packet be retransmitted continuously until successful delivery.…”

“…As monitoring and announcing data are not heavy compared to video, buffer capacity is not large. Furthermore, data time-tolive is basically short, the reservation is realistic and its benefits outweigh the storage cost [4].…”

Sender — Receiver cooperation and buffer observation for fine-grained adaptive transmission of video over mobile ad hoc networks

“…Perspective video communication over such networks can be expected in various field activities, such as disaster rescues, inter-vehicle information exchanges, and military operations. However, node movements, interferences, and environmental changes significantly intensify challenges against deployment of any communication service [1][2] [3]. Regarding distributed multimedia applications, given that traffic volume is heavy while packets are time-sensitive, delivery of such data is even more problematic.…”