WTCP ('Wireless Transmission Control Protocol') is a proxy-based modification of TCP that preserves the end-to-end semantics of TCP. As its name suggests, it is used in wireless networks to improve the performance of TCP. WTCP ('Wireless Transmission Control Protocol') is a proxy-based modification of TCP that preserves the end-to-end semantics of TCP. As its name suggests, it is used in wireless networks to improve the performance of TCP.