Trials first 2048QAM product in live operator network
Dragonwave has said that its 2048 QAM radios, launched in May 2012, have demonstrated a three times increase in capacity in a live operator demonstration.
Three microwave links in Intertelecom's test bed network in Odessa, Ukraine, have been equipped with the 2048QAM radios. DragonWave said that the field test has demonstrated the radios' ability to transport up to 37% more data through existing microwave channels. Through a combination of the 2048QAM modulation, dual channel operation and DragonWave's Bandwidth Accelerator feature, the test also achieved a threefold increase in capacity to more than 1.3 Gbps.
Higher modulation increases capacity on a radio link, but can reduce range, especially in heavy rain. Using Hitless Automatic Adaptive Modulation (HAAM) lessens that impact, Friesen said, by instructing the radio to operator at lower modulation rates when atmospheric conditions are an issue.
And using HAAM instead of XPIC (Cross Polarisation Interference Cancellation) means there is no need for a second radio to provide the cross-polarisation, reducing costs, Friesen said. The license cost for the 2048QAM feature is "significantly less" than adding more radios and a cross polarisation coupler for an XPIC scenario, he added.
"We explored other options for increasing link capacity such as XPIC, but we soon realised that coupling higher modulation modes with Hitless Automatic Adaptive Modulation allows us to meet the growing backhaul demands without needing to re-engineer existing links or purchase additional radios," said Boris Akulov, CEO at Intertelecom. "In effect, we have found a very cost efficient and streamlined means to triple our network capacity."
So is there a viable market for higher modulation microwaves in mobile backhaul? Geg Friesen, Vice President of Product Management, DragonWave, said that with 1.3Gb capacities, the key application would be in backhaul aggregation sites.
"We're starting to see a lot of customers want 300Mb to a cell site, so an aggregation of 2-3 links might well need more than Gig. Customers are requesting it [high modulation rates] in tenders. They're trying to get more out of their spectrum, so if they can achieve the 30% spectral efficiency increase you can with higher modulation rates, that's a practical asset." In the near term, Friesen said, backhaul upgrades would be driven by the capacity increases required by the move to LTE.
DragonWave recently acquired Nokia Siemens Networks' Horizon range of microwave products. 2048QAM modulation will also be coming to those products, Friesen said, but not until 2013 at the earliest.
Other vendors, such as NEC, have also announced 2058QAM microwaves, but Friesen said Dragonwave's approach is to do so without pursuing new hardware, offering higher modulations to its existing Quantum and Compact+ products as a software upgrade.