The Monarch Project

Protocols for Adaptive Mobile and Wireless Networking

The Monarch Project in the School of Computer Science at Carnegie Mellon University addresses the area of networking support for wireless and mobile hosts. Mobile hosts such as notebook and palmtop computers are now widely available and affordable, and many new wireless networking products and services are becoming available, including high-speed radio or infrared LANs and wide-area cellular systems such as CDPD. However, host mobility and the properties of wireless communication challenge some assumptions on which many current networking protocols have been designed.

Mobile users should be able to move about, communicating with each other and with wired or stationary hosts, each expecting and obtaining the highest level of service from their mobile hosts and from the network at any time. Mobile hosts should at all times be able to make use of the best available network connectivity, whether wired or wireless. With each change in location or type of network in use, the protocols and applications on the mobile host and on other hosts with which the mobile host is communicating should be able to adapt to the new characteristics of the mobile host's network connection. These changes include changes in the routing location, bandwidth, latency, error rate, and costs of the network in use. The focus of our work in wireless and mobile networking is to make this vision of adaptive mobile internetworking possible.

We are developing networking protocols and protocol interfaces to allow truly seamless wireless and mobile host networking. The scope of our research includes protocol design, implementation, performance evaluation, and usage-based validation, spanning areas ranging roughly from portions of the ISO Data Link layer (layer 2) through the Presentation layer (layer 6). The goal of this work is to enable mobile hosts to communicate with each other and with stationary or wired hosts, transparently making the most efficient use of the best network connectivity available to the mobile host at any time. We are currently studying mobile hosts operating in a large internetwork such as the Internet, mobile hosts operating in an ad hoc wireless network, and the interconnnection between ad hoc networks and an internetwork. We are also studying the affects of mobility on other network protocols such as reliable transport protocols, and the support for mobility in higher layer protocols and applications.

The name "Monarch" derives from the migratory behavior of the monarch butterfly. Each autumn, millions of monarch butterflies migrate from central and eastern United States and Canada to overwintering roosts in central Mexico; with the coming of spring, the monarch population again migrates northward. During migration, they may cover 80 miles or more per day. The name "Monarch" can also be considered as an acronym for "MObile Networking ARCHitecture".

Research Papers:

David B. Johnson, Last modified February 20, 1996.