Efficient Voice over Internet Protocol (VoIP) on Mesh Networks
MeshDynamics VOIP test in underground mine Mobile Military communications Tested VOIP Communications with SIP phones  

Besides the inherently high performance of MeshDynamics' patented multi-radio backhaul technology, additional specialized voice features minimize delay and jitter. These features insure that voice is transported rapidly and efficiently across the network, maximizing the number of voice calls that may be supported while minimizing wasted bandwidth. 

VOIP Performance Test Results by Spectralink (Polycom) underscore the superiority of MeshDynamics MD4000 products for VOIP over wireless mesh solutions. MeshDynamics demonstrated 12 VOIP clients on 802.11g - a record.  Polycom  Certification
Persistent VOIP.
Extensive testing has also been undertaken in Underground coal mines were VOIP phones are operating deep inside the mine sometimes 40+ hops from the wired connection. The phones are mobile while active. [Press Release
With our patented Persistent Mesh Technology (P3M), VOIP phones function even when the SIP gateway is not reachable: the mesh nodes act as a temporary proxy SIP server till nodes rejoin the main mesh. Press Release and Illustration.
Bulking VoIP over Wi-Fi:
Moving packets through a Wi-Fi network uses significant overhead. Combine this with the relatively small packets for VoIP that must be sent at regular intervals, (e.g. every 20 ms) and the overall system becomes increasingly inefficient. With more VOIP clients and as VOIP packets traverse multiple hops, latency and jitter performance degrades further in single backhaul radio products, due to contention on the same backhaul channel. MeshDynamics multi-radio multi-channel backhaul ensures deterministic latency and jitter by eliminating both the effects of single radio backhauls and involuntary contention. 

Patented VOIP concatenation engine  Since VOIP packets are small, inefficiencies related to transmitting small packets result in significant overhead. This adversely affects usable capacity. The Patent Pending MeshDynamics concatenation engine puts VOIP packets into a "container" packet. Containers are shipped periodically much like a bus arrives and leaves as a bus station at regular intervals. Bulk transport of VOIP packets is thus more efficient. Latency/jitter is also better managed than if the VOIP packets were individually transmitted - where they would be contending with each other. [Details]

Related Links:

1. MeshDynamics receives Prestigious VIEW certification Press Release on certification received from Spectralink/Polycom
2. MeshDynamics First With Persistent Voice Over Wireless Mesh VOIP calls work even when no SIP server is present. 
3.   MeshDynamics Delivers Persistent Wi-Fi Network for Mobile Environments  Merging and dispersal in mobile networks
4. Wi-Fi based Femtocell Extensions for the outdoor enterprise. Extension of Femtocell coverage using mesh.
5. VOIP and VIDEO on a City wide scale MeshDynamics VOIP Concatenation Engine explained..