JTP: An Energy-conscious Transport Protocol for Wireless Ad Hoc Networks

Within a recently developed low-power ad hoc network system, we present a transport protocol (JTP) whose goal is to reduce power consumption without trading off delivery requirements of applications. JTP has the following features: it is lightweight whereby end-nodes control in-network actions by encoding delivery requirements in packet headers; JTP enables applications to specify a range of reliability requirements, thus allocating the right energy budget to packets; JTP minimizes feedback control traffic from the destination by varying its frequency based on delivery requirements and stability of the network; JTP minimizes energy consumption by implementing in-network caching and increasing the chances that data retransmission requests from destinations "hit" these caches, thus avoiding costly source retransmissions; and JTP fairly allocates bandwidth among flows by backing off the sending rate of a source to account for in-network retransmissions on its behalf. Analysis and extensive simulations demonstrate the energy gains of JTP over one-size-fits-all transport protocols.Defense Advanced Research Projects Agency (AFRL FA8750-06-C-0199

Study of TCP Issues over Wireless and Implementation of iSCSI over Wireless for Storage Area Networks

The Transmission Control Protocol (TCP) has proved to be proficient in classical wired networks, presenting an ability to acclimatize to modern, high-speed networks and present new scenarios for which it was not formerly designed. Wireless access to the Internet requires that information reliability be reserved while data is transmitted over the radio channel. Automatic repeat request (ARQ) schemes and TCP techniques are often used for error-control at the link layer and at the transport layer, respectively. TCP/IP is becoming a communication standard [1]. Initially it was designed to present reliable transmission over IP protocol operating principally in wired networks. Wireless networks are becoming more ubiquitous and we have witnessed an exceptional growth in heterogeneous networks. This report considers the problem of supporting TCP, the Internet data transport protocol, over a lossy wireless link whose features vary over time. Experimental results from a wireless test bed in a research laboratory are reported