next up previous
Next: Effect of Communication Failures Up: Emulation Results Previous: Link Usage Probability

ES Mobility

ES mobility is a more difficult problem and will be examined in more detail as the RDRN project progresses. The parameters used in an emulation with mobile ES nodes are shown in Table 8. As mentioned in the section on the MYCALL Timer, if a MYCALL packet arrives after this timer has expired, a reconfiguration occurs. This could happen due to a new ES powering up or an ES which has changed position. Figure 18 shows the times at which reconfigurations occurred in a situation in which ES nodes were mobile. Based on the state transitions generated from the emulation it is apparent that the system is in a constant state of reconfiguration; no reconfiguration has time to complete before a new one begins. As ES nodes move, the NCP must notify RNs associated with an ES with the new position of the ES as well as reconfigure the ES nodes. To solve this problem, a tolerance, which may be associated with the link quality, will be introduced which indicates how far nodes can move within in a beam before the beam angle must be recalculated, which will allow more time between reconfigurations. It is expected that this tolerance in addition to Virtual Network Configuration will provide a solution to this problem.



Table 8:   Mobile ES Simulation Parameters.

Figure 18: Mobile ES Configuration Time.

Steve Bush
Tue Nov 12 11:48:31 CST 1996