Tropos bolsters multiradio wireless nets

Wireless mesh pioneer Tropos Networks has matched its rivals by unveiling a dual-radio access point that can use 2.4GHz and 5GHz radio bands to let customers more easily forge an outdoor mesh network.

One of the first wireless LAN and Wi-Fi mesh vendors, Tropos successfully has marketed a family of single-radio nodes: one 802.11b/g radio connects to wireless clients and to neighboring nodes using the Tropos routing protocol.

Rivals such as BelAir, Strix and Cisco offer products that use separate radios for client connections and for backhaul. Some products may have several radios dedicated to backhaul - one to only send, another to only receive - to maximize throughput. The dedicated radios potentially offer better performance, especially as the mesh network grows in the number of nodes and clients, and the extent of the area covered.

The first of the new products is the Tropos 5320 outdoor mesh node. It includes a 2.4GHz 802.11b/g radio, which can be used for client or mesh connections, and a 5GHz 802.11a radio, which currently is for backhaul connections.

A future version will let the 802.11a radio be used for both types of connections - and it's this promised feature that Tropos says distinguishes the 5320 from its rivals, some of which use only the 5GHz band for the mesh connections.

By being able to use the 2.4GHz band also, a network operator can create a mesh link where the 5GHz radio might falter because of buildings or dense trees. The lower bandwidth 2.4GHz radio can penetrate these obstacles more effectively.

Tropos says this dual-backhaul capability will lower the total cost of ownership (TCO) of large mesh networks, because network operators can use a 2.4GHz radio selectively instead of buying and installing more 5GHz radios to cover these problem areas. But large-scale, outdoor Wi-Fi networks are still so few that reliable TCO figures over time are hard to come by.

The new node will work with existing Tropos products.

The 5320 is scheduled to be available in October. Tropos prices its products on a square-mile basis. Covering one square mile with the new node will cost $90,000 to $100,000, which is about 30% to 40% above the cost of the company's current product line.

Tropos plans to add additional models over the next 12 months, supporting other radio technologies such as 802.16 WiMAX and various cellular standards.