Abstract: In this paper we use an analytical model to study how two radio networks : a primary network and a secondary network can coexist within the same area. We use a very simple protocol, Aloha, for both radio networks, and tools borrowed from stochastic geometry to model the performance of our two networks. We show that the primary network and the secondary network can adapt their transmission parameters simultaneously to achieve the following goal : the primary network maintains its performance with a maximum and fixed degradation whereas the secondary network maximizes its transmission throughput. In practice this involves the primary network adapting its transmission power and the secondary network its transmission probability. We also study the gain in performance when the secondary network nodes only transmit when their receivers are at minimum distance from any transmitter nodes in the primary network (constrained distance deployment). We obtain the following result : when there is no constraint used for the secondary network (free deployment), it can offer a low (but not completely negligible) density of successful transmissions when the capture threshold in primary network T1 is small. If we optimize the density of successful transmissions for the selected nodes in the secondary network which are transmitting to receivers at a minimum distance from any node in the primary network then the per node throughput for these selected nodes can be very significantly increased. However with this optimization the total network throughput for the secondary network is also slightly reduced. If we use a constrained distance deployment for the secondary network (only nodes whose receivers at a minimum distance from the primary network) the per node throughput can be very significantly increased and the total network throughput for the secondary network is increased.
Co-existence between the secondary and the primary networks based on the Slotted-ALOHA protocol is also explored in REF .
Coexistence of radio networks using Aloha
2010 IFIP Wireless Days
2010 IFIP Wireless Days
Computer Science