Modeling and control of IP transport in cellular radio links

• A fundamental assumption of the TCP protocol is that packet losses indicate congestion on the network. This is a problem when using TCP over wireless links, because a noisy radio transmission may erroneously indicate congestion and thereby reduce the TCP sending rate. Two partial solutions, which improve the quality of the radio link, are power control and link-layer retransmissions. We consider a radio channel with multiple users and traffic classes, and investigate how parameters in the radio model influences TCP-related quality measures, such as the average delay and the probability of spurious timeout. The results indicate that the outer loop power control is robust to uncertainties in the radio model. This robustness property supports separation between the radio layer design and the IP and TCP layers.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik -- Reglerteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering -- Control Engineering (hsv//eng)

Keyword

ARQ

Feedback control

Power control

TCP

WCDMA

Average delay

Cellular radios

Modeling and control

Multiple user

Outer loop power controls

Quality measures

Radio channels

Radio model

Retransmissions

Robustness properties

Sending rate

Spurious timeout

TCP over wireless

TCP protocol

Traffic class

Automation

Control

Radio broadcasting

Radio links

Robust control

Transmission control protocol

Radio transmission

Publication and Content Type

ref (subject category)

kon (subject category)