Packet radio communications provides an effective way to interconnect fixed and mobile computer resources. The ALOHA System at the University of Hawaii first introduced this capability in the context of a single-hop system using off-the-shelf RF equipment with all terminals within line of sight of the central station. The packet radio network described in this paper is 1) an extension of the basic Hawaii work to a geographically distributed system involving the use of repeaters to achieve area coverage beyond line of sight, and 2) provides added capabilities for authentication, antijam protection, and coexistence with other possibly different systems in the same band. An overview of the packet radio system concept is given in this paper.

A protocol that supports the sharing of resources that exist in different packet switching networks is presented. The protocol provides for variation in individual network packet sizes, transmission failures, sequencing, flow control, end-to-end error checking, and the creation and destruction of logical process-to-process connections. Some implementation issues are considered, and problems such as internetwork routing, accounting, and timeouts are exposed.

Abstract The design of the ARPA Computer Network brought together many individuals with diverse backgrounds and philosophies. In this paper, we review the methods used in the design of the Network from the vantage of over two years' experience in its development. The design variables, system constraints, and performance criteria for the network are discussed along with an evaluation of the tools used to design an efficient and reliable system. The design procedures and the conclusions reached about the network's properties appear to be generally applicable to message switched networks. Consequently, the results of this paper should be useful in the design and study of other store‐and‐forward computer communication networks.

In this paper, we discuss flow control in a resourcesharing computer network. The resources consist of a set of inhomogeneous computers called hosts that are geographically distributed and are interconnected by a store-and-forward communications subnet. In the communication process, messages pass between hosts via the subnet. A protocol is used to control the flow of messages in such a way as to efficiently utilize the subnet and the host resources. In this paper, we examine in some detail the nature of the flow control required in the subnet and its relation to the host flow control and subnet performance.

This paper treats the problem of the representation and reconstruction of signals from several sets of sampled values using a multiple-channel sampling and reconstruction scheme. Realizable and unrealizable solutions are presented for the optimum linear postfiltering and prefiltering operations. It is shown that the number of "independent" sets of samples which are necessary for the exact reconstruction of a signal is equal to the maximum number of overlappings of its sampled spectrum. This enables many different sampling expansions to be derived. The simultaneous optimization of the unrealizable linear prefilter and postfilter combination is carried out for the case where two sets of sampled values are taken. It is shown that with the optimum combination of filters, the angular frequency range of the input signal is limited by the prefilters to a total width of4\pi \rho, which is a natural extension of the single-channel result.

This paper treats some bandwidth properties of modulated signals of the formq(t) \cos [\omega_{c}t + \varphi(t)]where bothq(t)and\varphi(t)are modulating time functions. For such simultaneous amplitude and angle modulation (AAM), relationships are given connecting the bandwidth of the modulated signal with the properties of the modulating time functions. Some useful bounds on the bandwidth are found and a relationship is derived between the amplitude and the angle modulating functions which results in a minimum bandwidth. Several examples of such minimum bandwidth signals are given.