This chapter, concerned primarily with the design of digital radio networks whose nodes are not mobile, has two major weaknesses. First, the depth of coverage varies radically from one section to the next. For example, after a brief description of radio topologies, there are descriptions of the ALOHA system as an illustration of collision protocols and of DARPA’s PRNET as an example of packet radio networking. Intermixed with this introductory material is a discussion of more complex subject matter, such as spread spectrum modulation and multipath waveforms. This is followed by an introduction to broadcast protocols, including an explanation of CSMA. The remainder of the chapter deals with the 1970’s PRNET system, its protocols, routing, error control, and topology. Given the similarities between PRNET and the early ARPANET, references to the earlier chapters on ARPANET would have been useful.

The second and more critical problem is that the whole discussion is so dated that it is wrong in many places. There are no references to any work after 1980. Earth stations and satellite dishes are characterized as being too expensive to be in general use. There is no recognition of the possible use of satellites as a central control for terrestrial-based stations integrating mobile services and overcoming line-of-sight limitations, which was theorized in 1983 (for discussion of this topic, see [1] and [2]) and has already been implemented. The line-of-sight limitation on packets has also been resolved without having to resort to satellites. There is no discussion of developments in fault-tolerant broadcast protocols [3,4]. The technology of packet radio is changing rapidly, and packet radio systems are becoming quite common. There are mobile terminals in police cars, mobile libraries access central card catalogues, utilities use packet radio to monitor power fluctuations, and it is used in some alarm systems. It is a mistake to limit the discussion to immobile terminals and to present packet radio as an experimental technology whose time has not yet come.