A new header compression scheme for TCP streams in IP based wireless networks

The current trend in the telecommunication world is the proposal of a universal telecommunication system deriving from the convergence between mobile telephony and data transmission. To achieve such a convergence in an efficient way, it is presumably necessary to utilize a network platform totally based on TCP/IP architecture (an 'All-IP Network'). However, the encapsulation process of TCP/IP wastes a substantial part of the radio channel bandwidth for the transmission of control information (header) that does not have any specific function at radio level. Since this bandwidth is generally the most expensive and limited resource for wireless networks, it is necessary to adopt a header compression scheme that can reduce the protocol overhead while working efficiently and robustly under noisy links with time-variant BER conditions. In this paper, a new header compression scheme for TCP streams as a specific header compression profile within the IETF ROHC (robust header compression) framework is proposed and analyzed through simulations exploiting network simulator (ns-2). The proposed scheme, compliant with IETF requirements for TCP/IP header compression, is based on the distinct management of data and acknowledgment (ACK) streams associated with the TCP connection and exploits a robust header encoding technique for reducing the effect of error propagation. The results obtained, in terms of throughput, overhead and goodput, are reported as a function of bandwidth and BER. A comparison with the results obtained without compression allows us to evaluate the performance of the proposed compression scheme in a realistic and dynamic environment