Issue No. 01 - February (1996 vol. 16)
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/40.482311
As the trend towards smaller, lighter and more powerful computers continues, mobility and wireless connectivity become increasingly important. The MosquitoNet project is studying issues in wireless and mobile computing, and this article presents our performance analysis and observations of one of the emerging wireless technologies: the Metricom Microcellular Digital Network (MCDN). Metricom provides one of the best combinations of bandwidth, coverage area and cost for a wireless data network. We find that the throughput of their radio devices is ccomparable to a modern modem, but the latency, or round-trip delay, is much higher. The maximum throughput we measured was 30-40 Kbits/second, but the minimum latency for even the smallest IP packet is at least 60ms. We have experimented with both the datagram and Hayes modem emulation modes of Metricom's wireless radios. We are early users of the datagram mode, and our experiences confirm two sometimes-forgotten principles. First, packet switching allows more efficient sharing of resources than does circuit switching. Second, interfaces that are satisfactory for use by human beings often show their flaws, ambiguities and omissions when used as programming interfaces for software control of devices.
Wireless networks, networking, packet switching, interconnects, mobile computing
S. Cheshire and M. Baker, "A Wireless Network in MosquitoNet," in IEEE Micro, vol. 16, no. , pp. 44-52, 1996.