the handsets from one base station to another each base station is equipped with a three sectored antenna with each sector covering 120 u00b0 in azimuth along with a feasible deployment scenario the base station locations are carefully planned in addition the orientation of the sectors is pre determined and remains fixed throughout the operational lifetime of the network notice that in fig1 the sector orientation is symmetric i e all the sectors with the same number are pointing in the same direction for example the first sector of each base station is facing south in the preferred embodiment all of the base stations are using the xmax signal to communicate with handsets in their coverage area in addition the communication is carried over the ism band near 900 mhz due to the inherent nature of a xmax signal only one frequency channel is available in the system all the base station 39 s clocks are synchronized numerous solutions exist for achieving clock synchronization that are well known to those skilled in the art for example network timing protocol ntp version 3 described in rfc 1305 or simple network timing protocol sntp described in rfc 2030 can be used more information on both the protocols can be obtained from the www ntp org website gps is also an option to synchronize the base stations the basic idea for using xmac in multi base station deployment involves scheduling all the sectors with the same number concurrently to accomplish such a schedule the time domain is sliced into equal intervals of time referred to as hyper frames as shown in fig2 each hyper frame is in.