Public Safety Voice Legacy vs. LTE Broadband Future

Aviat-at-IWCE-public-safety-LTE-broadband-microwave-backhaulIWCE 2013 (International Wireless Communications Expo), March 13-14, was a tale of two different but related stories. The first was the continuing enhancement of legacy P25 voice-centric products/features/ applications and the second was discussion of the LTE broadband data-centric network plan/products/ solutions of the future.

P25 continues to be the only source of mission-critical voice, and the consensus is that will not change for maybe 10 more years—or longer. We saw really cool product enhancements from Motorola and Harris. Clearly, there is plenty of investment continuing in P25, and vendors believe they will get a return on that investment. There is still a tremendous amount of work to be done on going from analog to digital systems and wideband to narrowband.

In contrast, LTE broadband will probably take another 1.5 years just to get to the stage of RFQs. However, we did see a lot of innovative technology and interoperability demonstrations. Who would have thought that Harris handheld radios would be located in the Alcatel-Lucent booth and Motorola in the Raytheon booth?

There were many talks on FirstNet strategy and planning. Chief Dowd said FirstNet would announce a general manager within a couple weeks…let’s hope it is a public safety professional with many years of experience in setting up mission-critical networks. Of course, the industry pundits were there to discuss their view of this enormous challenge…unfortunately it appears the thinking is still very divergent…which can only mean that someone is going to be disappointed by the decisions FirstNet will make.

Many provider-based discussions were also held. For example, Aviat’s own Gary Croke gave a presentation on the considerations that any organization must make for high-speed backhaul and how microwave fits into those.

Lastly, we heard some excellent talks on engineering this network. Skilled network designers like Bob Shapiro gave us some insight into how the LTE network will look different from P25 networks (e.g., number of basestations, capacity of traffic, complexity of design). Good news is the industry is developing some excellent design tools to aid in designing the network.

The signs are positive for the public safety industry. IWCE show attendance was good, vendors showed up with real innovation and investment in new products, the Public Safety Broadband Network continues to move ahead…cannot wait for APCO in the fall!

Randy Jenkins
Director Business Development
Aviat Networks

Microwaves Could Solve Need for Long-Haul, Low-Latency Networks

Microwaves Could Solve Need for Long-Haul, Low-Latency Networks (via slashdot)

While high-speed optical fiber might be the way to go for large national research networks, point-to-point microwave connections have emerged as key links between financial exchanges.  The reason? Ultra-low latency. With widespread interest in sending the timeliest data possible, two separate microwave…

Critical Role of Microwave in LTE and Small Cell Backhaul

Mobile backhaul has become one of hottest and most contentious subjects in telecommunications ever since LTE cellular phone technology started to ramp up. One much overlooked aspect of deploying LTE lies not in the capacity required to backhaul cell site traffic but the effort required to build out the required sites. It is really about site surveys, frequency coordination, engineering, planning and installation. Aviat Networks’ chief technology officer (CTO), Paul Kennard, addressed this dichotomy and others related to LTE in his presentation to the IEEE’s Communications Society.

Although, Paul did have plenty to present regarding capacity. For example, with proper use of rings, overbooking, QoS, XPIC and other techniques and technologies, microwave backhaul can provide 400 Mbps-plus throughput. Compare this to the realistic throughput demands of a typical LTE site that max out at about 100 Mbps.

He also delved into the emerging backhaul category for Small Cells—designed to supplement traditional cellular infrastructure. The fact is that traditional techniques of deploying cellular macrocell basestations will be insufficient to provide broad enough coverage for this LTE wireless technology. To augment macrocell coverage for LTE mobile telecommunications providers have been investigating, trialing and, in some cases, deploying one or more of several small cell technologies (e.g., picocell, microcell, femtocell). Consequently, new methods will be needed to backhaul traffic from Small Cell sites.

Fiber backhaul may not be available at all small cell sites and when it is it could be very expensive to trench long distances. Regular line-of-sight (LOS) microwave with its parabolic dishes could prove aesthetically unsuitable for many Small Cell locations and/or difficult to install. Non-line-of-sight (NLOS) microwave and millimeter-wave point-to-point and point-to-multi-point wireless may have their applications, but their latency of 5-10 ms may be too much for real-time applications and voice—not to mention licensed spectrum is costly and unlicensed spectrum is very risky due to interference issues.


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Building Ultra-Long IP Microwave Links


Ultra-long microwave links between backhaul towers enable long-distance telecommunications in the Mojave Desert. Photo credit: °Florian / / CC BY-SA

Designing and engineering microwave radio networks has always been challenging and a bit of an art—especially when they are ultra-long point-to-point wireless networks. In an article published February 25, 2013, Aviat’s solutions architect Charles Dionne outlines some of the key considerations that need to be made when designing and building these ultra-long microwave backhaul links for point-to-point wireless networks.

The article on RCR Wireless provides an overview and detailed checklist of the relevant items for designing ultra-long point-to-point wireless microwave links including:

  • Site selection
  • Frequency selection
  • Antenna size
  • Atmospheric conditions

Readers will take away more than just a laundry list of potential pitfalls; they will gain an enhanced appreciation of the very specialized skills and thorough understanding of microwave technology that is necessary for successfully implementing point-to-point wireless microwave backhaul.