Questions on TCP for cellular networks

Base station has a finite buffer, drop-tail gateway
Simulation parameters
o Finite buffer size B in packets at the base station
o Bandwidth U in packets/second of the bottleneck link from base station to mobile host
o End to end propagation delay D in seconds
TCP performance analysis
o Throughput of TCP-Reno and TCP-Tahoe drops significantly when packet loss exceed
o Snoop and ELN-ACK maintain a high throughput even at high packet loss rates
o Explicit notification of cause of packet loss in ELN-ACK provides better performance in low
bandwidth wireless channels
Conclusions on TCP
o TCP needs modification to perform efficiently for use on networks with wired and wireless segments
o Conventional assumption of loss=congestion is inaccurate in wireless networks
o Explicit loss notification with ACK technique is a solution that is more efficient than other techniques
TCP for cellular networks
o 2G/3G cellular networks have high PHY latencies due to processing, and has asymmetric data rates
o For good TCP performance, need large TCP congestion window (especially for loss recovery in long
thin networks)
o Recommendations: TCP SACK, TCP ECN, or TCP New Reno