Abstract: Location related information is collected for a network of communication devices that each is operable in a coordinating mode and in a non-coordinating mode. While in the coordinating mode, each communication device collects and stores location determining information (410, 420). Using the location determining information collected by one or more of the communication devices over multiple instances of operation in the coordinating mode, location information is calculated or updated for selected devices within the network (510, 520, 530, 540). In one embodiment, each device operates to mediate communication activities among others devices of the network while in the coordinating mode.

Abstract: A system and method for orthogonal modulation of signals in communication systems. In the transmitter, differentially coded symbols are used to select time-shifted code sequences. The timing, or code position, of a code sequence is determined at the receiver by comparison to the previous code from the same channel, thus eliminating the need for dual-channel transmission and eliminating error due to differences in path propagation time. A fixed preamble code is also used to synchronize the receiver.