Wireless networks consist of many nodes each having a wireless modem. All modems share the smae frequency channel and so transmissions can interfere with one another. However by choosing the power levels appropriately, several simultaneous transmissions can take place. By relaying packets in a multi-hop mode, nodes can communicate with one another.

In this lecture we will sharply characterize the amount of traffic that wireless networks can carry. We will show that when nodes are optimally arranged, then each node can transmit about c/sqrt(n) bits/sec to its destination. If however the nodes are randomly located, then the capacity is even less, about c/sqrt(n log n) bits/sec.

We will also mention several implications of these results that designers may want to take into consideration. These include the sizes of networks that may be tolerated by users, the power consumption for communication purposes by mobile users, the range of transmissions, etc.