INTEGRATION OF MOBILE STATIONS INTO FIXED NETWORKS

Gerald Maguire, KTH Computer Communication Systems

Integration into the Internet (TCP/IP)

One goal of this project is to realize a user transparent TCP/IP router device for wireless links (infrared / radio) operating at 1-10 Mbit/sec. The device for the mobile host and for the basestations can be realized by the same kind of hardware but with different kinds of communication software. The device called MINT (Mobile IP Router) consists mainly of three parts, one for the connection to the host or backbone (Ethernet), one for connecting to the wireless LAN (radio or infrared), and a processing part for computing the communication protocols. Such devices thus serve as more than mobile modems, i.e. they actually route packets over potentially multiple paths with varying connectivity and quality. The MINT hardware and has been developed in a pre-project phase in conjunction with HP Labs (Palo Alto)

By using Ethernet as an input channel, it should not be necessary to install special purpose wiring dedicated to mobile communication. Instead the existing network, which normally is globally available, is used to select suitable sites for base stations.This approach has some major advantages. It localizes all specific hardware and software efforts in a local device which is compatible with most host computers. The operating system in the host computers need not require modifications in order to support basic mobility.

This project builds upon the existing work on Mobile-IP protocols for TCP/IP which has already been done at Columbia University. The current project seeks to go beyond the level of ~10 of machines to find out more about the correlated traffic effects, the effects of scaling the wireless network up, how to achieve high transmission rates at low cost, etc. To realize a large scale field trial the new router must be low in cost, size, and power consumption while offering high performance.

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