A Lower Bound for the Achievable Throughput in Large Random Wireless Networks Under Fixed Multipath Fading

Abstract

We consider the problem of achievable per-node throughput in an extended distributed wireless network where the node locations are random and the channel attenuation between pairs of nodes exhibits independent random multipath fading.In [1] a clever protocol construction based on percolation theory was used to show that a per-node throughput of a constant times 1 √ n bits per second is achievable with probability approaching one as the expected number of nodes in the network, n, becomes large (i.e. w.h.p.), for networks with random node locations under a deterministic channel gain modeling path-loss and absorption.We use a similar approach to extend the result to a more realistic channel gain model where the channel gains are random due to multipath effects. In particular, we show that a constant times 1 √ n bps node is also achievable, w.h.p., when the channel gains are random. The result applies to independent, frequency flat fading channel models where the tail probability exhibits an exponential decay (e.g., any mixture of line of sight and Rayleigh, Rice and Nakagami distributions).

Security-capacity trade-off in large wireless networks using keyless secrecy

“…It can be noted that the conditions on f (n) forbid us from achieving the per-node throughput of Ω(n −1/2 ), as obtained in [3,11]. But as we will see later, the asymptotic reduction in throughput allows us to tolerate a non-trivially large number of eavesdroppers.…”

“…But as we will see later, the asymptotic reduction in throughput allows us to tolerate a non-trivially large number of eavesdroppers. Similar to [3,11], our construction uses percolation theory to show the achievability result. However, our construction differs from those in [3,11] in two crucial aspects:…”

“…• Secondly, the fact that links experience time varying fading in our model necessitates a substantially different relay selection algorithm in comparison with prior work, which either assume non-fading channels [3] or static fading channels [11].…”

“…Similar to [3,11], our routing protocol involves three phases: 1. The draining phase in which a source transmits a packet to a nearby"entry point" situated on a horizontal crossing path.…”

“…In contrast to the routing strategy in [3,11] where the nodes on a routing path are fixed over the entire set up, we opportunistically choose a relay node at each hop that has a sufficiently large fading gain.…”