Abstract: The interference on the available communication frequencies is measured during an idle time slot over a first period of time at a first rate. The available frequencies are prioritized based on the interference measurements, and a list is formed of the frequencies having the lowest interference measurements. Interference measurements are made at a second rate, greater than the first rate, for a second period of time less than the first period. When a call is assigned, the interference level requirements for the call are given, and the carrier power level of the call is measured. The carrier-to-interference ratio of each frequency in the list is determined using the second interference measurements and the measured carrier power. The frequencies in the list meeting the interference level requirements for the call are then selected, and frequency hopping while serving the call is performed using the selected frequencies.

Abstract: A process assigns frequency channels to service communications in a cellular wireless system. The process includes performing a simulation of the system to produce a plurality of lists of channel rankings and assigning the lists of produced channel rankings to the base stations for use in assigning channels to service communications with mobile units. The simulation evolves the lists of channel rankings according to an algorithm that dynamically reduces inter-communication interference. Individual lists of channel rankings prioritize the channels for servicing communications by associated individual base stations.

Abstract: A communications system and method of ordered borrowing which facilitates dynamic access to a global channel set that has been partitioned into subsets, with each cell of the system being assigned a particular subset of the channel set. The assignment of channel subsets is performed in such a way as to respect various constraints imposed by the physical layout. Calls originating in a cell are first assigned to the channels allocated to the base station of that cell, in an order determined by the cell. Once the allotted channels are exhausted, i.e. in the busy state, the cell attempts to borrow channels from those allotted to the base stations of neighboring cells in a specified order. The borrowing cell borrows a specified number of channels from each neighbor before returning to a particular cell to borrow additional channels. The channels borrowed from a neighbor are accessed in an order which is substantially the reverse of the order in which they are accessed by the owner cell.

Abstract: Efficient simulation is achieved by employing a highly efficient ordering of the events to be simulated. Specifically, the events to be simulated are grouped into layers and the layers are simulated in order. Each of the layers consists of events that are either strictly independent of the other events in the layer or are dependent of other events in the layer but possess a particular attribute. That attribute is one that permits the use of an associative operator. This operator allows the simulation of N events in O(log N) computation iterations.

Abstract: A discrete event simulation system that avoids all blocking and advances the simulation time in an efficient manner by treating the simulated system as a set of subsystems and simulating the subsystems concurrently. The simulation proceeds iteratively by restricting the simulation of scheduled events for each subsystem at any one time to a chosen simulated time segment (bounded lag) beginning with the lowest simulation time found among the subsystems. With each simulation iteration, an "at risk", demarcation time is evaluated based only on a subset of the subsystems that can potentially affect the simulation at the considered subsystem. Events scheduled for a time earlier than the "at risk" time are simulated.