The capacity of wireless networks：（无线网络的能力）.pdfVIP

388 IEEE TRANSACTIONS ON INFORMATION THEORY, VOL. 46, NO. 2, MARCH 2000 The Capacity of Wireless Networks Piyush Gupta, Student Member, IEEE, and P. R. Kumar, Fellow, IEEE Abstract—When identical randomly located nodes, each ca- example of such networks is multihop radio networks or ad pable of transmitting at bits per second and using a fixed range, hoc networks. Another possibly futuristic example, see [1], may form a wireless network, the throughput ( ) obtainable by each be collections of “smart homes” where computers, microwave node for a randomly chosen destination is  bits per ovens, door locks, water sprinklers, and other “information ap- log second under a noninterference protocol. pliances” are interconnected by a wireless network. If the nodes are optimally placed in a disk of unit area, traffic It is to these types of all wireless networks that this paper patterns are optimally assigned, and each transmission’s range is is addressed. Such networks consist of a group of nodes which optimally chosen, the bit–distance product that can be transported communicate with each other over a wireless channel without by the network per second is ( ) bit-meters per second. any centralized control; see Fig. 1. Nodes may cooperate in Thus even under optimal circumstances, the throughput is only routing each others’ data packets. Lack of any centralized con-  bits per second for e