trategy: Randomly select K receivers for equal doses of jam- ming energy, each receiving EJK1 units. The remaining channels are not jammed. The quantity Ks is referred to as the diversity factor of the communication system complex. When Ks exceeds unity, the receiver must employ a diver- sity combining algorithm to convert the outputs of the Ks chosen links into a single output for the system user. The performance measure to be employed here, in determining the effectiveness of these strategies, will not depend on specifying a particular diversity combining algorithm. The randomness required of these strategies should be interpreted as meaning that the corresponding adversary has no logical method for pre- dicting the choice of strategy, and must consider all strategies equally likely. Furthermore, random selection of communication links by the transmitter should not affect communication quality since all available links are assumed to have equal attributes. (Examples of link collections with non-uniform attributes will be considered in Part 2, Chapter 2.) Energy Allocation Strategies The receiving complex, having knowledge of the strategy selected for communication, will collect all Es units of transmitted energy in the Ks receivers remaining in operation. However, the amount of jamming energy collected by those same Ks receivers is a random variable whose value is determined by which of the (K) jamming strategies is selected (:) denotes a binomial coefficient). Under the equally likely strategy assump- tion, the probability that the jammer strategy will include exactly N of the Ks receivers in use, is given by (1.12) otherwise where Nmin = max(0, KJ + Ks-K) (1.13) Nmax = min(K), K ). (1.14) Using (1.12)-(1.14), it is possible to compute the expected total effective jam- ming energy EJeff sensed by the Ks receivers, namely (1.15) E being the expected value operator. Despite the complicated form of Pr(N), it can be verified that E{N} = K,Ks, (1.16) and hence, that E Jeff (1.17) More generally, it can be verified 