Just as wireless transmission use has grown by leaps and bounds in the past few years, so too have operator backhaul needs.
Microwave transmission has historically played a large role in backhaul transmission, but most microwave network topologies were relatively inefficient. Microwave transmission has historically relied upon daisy chain and tree network topology, avoiding ring topologies because of their need for dedicated protection capacity.
This has changed with the emergence of the ITU-T G.8032v2 packet microwave standard, making microwave backhaul more efficient and ushering in a resurgence of ring network design.
With the ITU-T G.8032v2 standard, traffic is sent in two directions around a ring, effectively doubling capacity. It also offers reduced capital expense by eliminating the need for fully protected sites.
“This standard was designed to address IP and LTE (News - Alert) packet network requirements while also efficiently exploiting the inherent advantages of ring based network topologies,” noted Paolo Volpato, product strategy manager for wireless transmission at Alcatel-Lucent (News - Alert) in a recent TechZine posting, Packet Microwave Rings Optimize Capacity and TCO. “Given these advantages, together with the explosive capacity demands to support new LTE based services it didn’t take long for ITU-T G.8032v2 implementations to get deployed.”
A recent mobile backhaul packet-microwave deployment by Alcatel-Lucent in the Middle East and Africa region puts numbers to the advantages. The ITU-T G.8032v2 based network design doubled microwave link capacities and increases network capacity at key points in the network by leveraging the ring topology’s ability to double network capacity.
Alcatel-Lucent also found that the ring-based approach resulted in the need for 36 percent fewer microwave radio outdoor units, even though the design required five more interconnected microwave network sites (23 versus 18).
“Even though the ring approach required a few more interconnected microwave network sites/links together with supporting antennas, the overall expense of the increased number of antennas was counter-balanced by a reduction of antenna size,” wrote Volpato. “Nearly 80 percent of the antennas had a diameter of either 30 cm or 60 cm (1 or 2 feet respectively). This size reduction is extremely important since smaller size antennas require less space on microwave towers and reduced installation effort, further minimizing network TCO.”
Edited by Peter Bernstein