Impact of Mobility on the BER Performance of Ad Hoc Wireless Networks

Gianluigi Ferrari, Ozan K. Tonguz
2007 IEEE Transactions on Vehicular Technology  
In this paper, the authors quantify the impact of mobility on the bit error rate (BER) performance of ad hoc wireless networks. Analytical expressions, relating the BER at the end of a multihop route with the mobility characteristics of the nodes and the switching strategy, are derived on the basis of a rigorous detection-theoretic approach. In particular, two network switching scenarios are considered: 1) opportunistic nonreservation-based switching (ONRBS), where a message flows from source
more » ... destination by opportunistically choosing the available shortest consecutive links and 2) reservation-based switching (RBS), where, after the creation of a multihop route from source to destination, the message is "forced" to flow over the reserved links, regardless of their actual lengths. The network performance is evaluated for both an ideal case (without interference) and a realistic case (with interference). The improved robustness against mobility offered by ONRBS, with respect to RBS, is analyzed and quantified. In particular, two node mobility models, known as directionpersistent (DP) and direction-non-persistent (DNP), are considered, and it is shown that DP mobility causes a much more profound degradation in the end-to-end route BER than DNP mobility. This conclusion is more pronounced in ad hoc wireless networks employing RBS. Overall, the results show that if the medium access control (MAC) protocol is not efficient in canceling or mitigating the interference, then the role of the switching/ routing strategy in network performance is quite minor. Index Terms-Ad hoc wireless networks, internode interference (INI), mobility, nonreservation-based switching (NRBS), RBS. 1 This MAC protocol was incorrectly referred to in [16] and [17] as the Aloha MAC protocol, for its resemblance, in terms of route activation being independent from the activity of other nodes in the network, with the classic Aloha MAC protocol [20] . However, there are significant differences that make the proposed protocol different from the classic Aloha MAC protocol: 1) multihop route reservation and 2) no use of retransmission techniques. 0018-9545/$25.00 © 2007 IEEE Italy, in November 1974. He received the "Laurea" degree (five-year program) (summa cum laude) and the Ph.D. degree in electrical engineering from the
doi:10.1109/tvt.2006.883790 fatcat:2efbbakqafhhvdrxidzxrrsmdy