Unit 5: Transport Layer & Wireless Application Protocol (WAP)

The Catastrophic Failure of Traditional TCP in Wireless Environments The Transmission Control Protocol (TCP) is the foundational transport layer protocol of the internet, guaranteeing reliable, ordered delivery of data. However, it was architected in the 1970s for highly reliable, wired fiber-optic and copper networks. In these pristine environments, the physical Bit Error Rate (BER) is infinitesimally small (often less than 10^-9). Consequently, the original designers of TCP made a hardcoded, fundamental assumption: if a packet is lost in transit and fails to generate an Acknowledgment (ACK), it is almost certainly because an intermediate router became overloaded and its memory buffer overflowed. This is the definition of Network Congestion. ...

The Crisis of the Early Mobile Web In the late 1990s, the telecommunications industry faced a monumental challenge: attempting to merge the rapidly expanding World Wide Web with the highly constrained physical realities of early cellular networks. Mobile hardware of that era was primitive. Phones possessed CPUs operating in the low Megahertz, mere kilobytes of RAM, and tiny monochrome screens incapable of rendering graphics. More importantly, they communicated over 2G GSM networks providing a maximum theoretical throughput of 9.6 kbps, suffering from severe latency and constant radio disconnects. ...