- December 18, 2015
- 70 GHz, 80 GHz, AT&T, FCC, Federal Communications Commission, Fixed Wireless Communications Coalition, FWCC, mobile, small cell backhaul, T-Mobile, wireless
AT&T and T-Mobile recently filed comments with the FCC that will enable small cell backhaul in urban cores for greater subscriber connectivity.
In the last few weeks, the future prospects of small cell antennas got brighter and shrank at the same time. AT&T and T-Mobile both filed comments with the Federal Communications Commission (FCC) in support of an industry-wide waiver of rules against flat-panel antennas for backhaul radios in the 70-80GHz bands. Currently, out-of-date FCC regulations about antenna radiation patterns hold back development and deployment of this type of equipment that urban dwellers will find acceptable in big city cores.
The current rules effectively call for the use of parabolic antennas that will be unsightly and would violate the aesthetics considerations and zoning regulations in many city core locations—precisely the type of environment that 70-80GHz radios exist to service. While the FCC regulations seem to necessitate parabolic antennas to keep radio beams focused and from interfering with equipment in the vicinity that uses the same wavelengths, mobile subscribers prefer more visually friendly solutions.
How to get from here to there
For the last few years, Aviat Networks has been working with the Fixed Wireless Communications Coalition and others to get the FCC to update its regulations in the 70-80GHz bands. The problem: when the FCC promulgated these rules, the idea had never occurred to anyone that these bands would ever service small cell applications. And the applications that the FCC’s 70-80GHz rules were designed to support never materialized, with only 5,500 links registered in this spectrum since 2005, according to T-Mobile.
However, with this breakthrough in support from Tier 1 operators like AT&T and T-Mobile, the FCC should feel reassured that granting the waiver to the antenna rules for 70-80GHz bands is in the best interest of all the wireless industry service providers. And with OEMs in addition to Aviat asking for the waiver, no specific vendor will be favored. We urge other wireless service providers, communications equipment OEMs, subscribers and anyone else interested in moving forward as fast as the technology can go to also contact the FCC about granting this industry-wide waiver.
In the meantime, to learn more about urbanized small cell backhaul in the 70-80GHz bands, download this white paper.
- March 30, 2015
- Cell site, intelligence, Layer 3, microwave networking, Microwave Router, mobile, mobile cell sites, mobile sites, regular router, smart devices, White Paper, wireless, wireless traffic
Once upon a time, cell sites served as little more than passive pass-throughs for phone calls and text messages. Because voice calls and SMS posts did not require much wireless capacity cell sites did not require very robust provisioning. Now that the Internet has gone fully mobile with streaming videos and real-time applications such as VoLTE and IPTV regularly crushing network capacity design parameters, the time to get smart about backhaul and access traffic has arrived. The time for Layer 3 intelligence is now.
In fact, for some time mobile cell sites have transitioned from simple Layer 2 connected sites for 1990s-style mobile phone and data access to multipurpose centers for delivering new, smart device services. However, they can only provide new, smart services if they are built upon Layer 3 technology that offers intelligent handling of wireless traffic. Only IP routing technology is capable of such functionality.
But here comes the catch regarding IP routers providing Layer 3 intelligence at the cell site. With more than 50 percent of the wireless traffic in the world going to and coming from mobile sites through backhaul radio, Layer 3 intelligence must have awareness of microwave networking. And regular routers just do not offer microwave awareness. A new class of device must fill the void left by regular routers that frankly do not have enough “smarts” to deliver Layer 3 intelligence for cell sites that depend on microwave backhaul. A device that combines the best attributes of microwave radios and IP routers.
To provide a closer examination of this issue, Aviat Networks has authored a new white paper—no registration required—that makes the case for Layer 3 intelligence at the cell site. And how to implement a new class of “smart” devices that enable microwave radio awareness with IP routing.
- December 19, 2013
- Aviat Networks, Digital terrestrial television, Hertz, mobile broadband, Ofcom, Radio spectrum, Spectrum of a ring, Telecommunications, White Space, wireless
On Dec. 16 2013, Ofcom—the UK telecom regulator—announced a new approach for the use of E-band wireless communications in the United Kingdom. This new approach results from an earlier Ofcom consultation exercise in which Aviat Networks participated.
To summarize, the new approach, which is available for licensing after Dec. 17, 2013, splits the band into two segments. Ofcom will coordinate the lower segment of 2GHz, while the upper segment of 2.5GHz will remain self-coordinated as per the prior policy.
The segment Ofcom coordinates will follow the usual regulatory processes for all the other fixed link bands it oversees. Moreover, Ofcom has already updated all the relevant documents and forms to accommodate E-band. While we (i.e., Aviat Networks, other telecom vendors) would have preferred the larger portion of spectrum to have been granted to the Ofcom-coordinated process, we welcome this new arrangement because it provides an option for greater security and peace of mind to operators in terms of protection from interference than was envisaged for the previous all self-coordinated spectrum regime.
For a more detailed look at the new E-band arrangement, Figure 1 shows the Ofcom-coordinated section sitting in the lower half of both the 71-76GHz and 81-86GHz bands thus allowing for the deployment of FDD systems in line with ECC/REC(05)07.
Figure 1: Segmented Plan for Mixed Management Approach (click on figures to enlarge)
In terms of channelization within the Ofcom-coordinated block, the regulator announced that it would permit 8 x 250MHz channels, 4 x 500MHz channels, 1 x 750MHz channel and 1 x 1000MHz channel as per ECC/REC(05)07. Ofcom also stated that 62.5MHz and 125MHz channels will be implemented as soon as the relevant technical standards, etc., from ETSI are published. Figure 2 shows the Ofcom channel plan:
Figure 2: Ofcom Permitted E-band Channelizations
Regarding equipment requirements, Ofcom stated that it will allow equipment that meets the appropriate sections of EN 302 217-2-2 and EN 302 217-4-2. This includes the antenna classes (e.g., classes 2-4) that will allow the deployment of solutions with flat panel antennas. Aviat Networks welcomes this approach and hopes that other regulators—notably the FCC in terms of antenna requirements—currently considering opening up and/or revising their rules for E-band adopt similar approaches.
The license fees for the self-coordinated segment remains at £50 per link per annum, whereas in the Ofcom-coordinated segment the fees are bandwidth based as reflected in Figure 3:
Figure 3: Ofcom Bandwidth-based Fees
Notwithstanding the current fees consultation process that Ofcom is undertaking, these “interim fees” will remain in place for five years, after which time the results of the fees review may mean that they will be amended.
Also because of responses received during the consultation process, within the self-coordinated block, Ofcom will now require the following additional information for the self-coordination database: antenna polarization (horizontal, vertical or dual), ETSI Spectrum Efficiency Class and whether the link is TDD or FDD.
- October 8, 2013
- Aviat Networks, backhaul, frequency bands, Ian Marshall, microwave, Radio spectrum, small cell, Spectrum, Telecommunications, White Paper, wireless
Small cell will enable mobile usage in dense urban environments but will need a backhaul solution to make it possible. Photo credit: Ed Yourdon / Foter / CC BY-SA
The Case for Small Cell Backhaul
As the search for frequency bands with suitable capacity for small-cell backhaul continues, frequency bands above 50GHz start to appear attractive because they offer both high-bandwidth availability and short range owing to their inherent propagation characteristics. The white paper available at the bottom of this blog examines spectrum in the 57-64GHz range to see whether it can be of use for small cell backhaul.
In many countries, the frequency range 57-66GHz is split into a number of discrete bands with differing requirements and conditions of use and/or licensing. These differences will be highlighted where applicable.
From a global point of view, the use of this spectrum by Fixed Services (FS) is being addressed by the ITU-R in its draft report on Fixed Service use trends in WP5C, which is currently under development and states:
57 GHz to 64 GHz
The radio-frequency channel and block arrangements of these bands for FS are defined in Recommendation ITU-R F.1497.
In 2011, around 700 links were in use in this band in a few administrations. The majority of the links are used for fixed and mobile infrastructure.
The air absorption around 60 GHz is over 10 dB/km. This condition restricts the hop length; on the other hand, the spectrum reuse efficiency is high. This feature makes the band suitable for small cell mobile backhaul.
Clearly, a global reported usage of 700 links would suggest a great deal of underutilization, although with unlicensed use in many countries it is difficult to know whether these figures are accurate or not. Regardless, there are reasons as to why this could be the case, while noting that the ITU-R believes this band has potential for small cell backhaul.
One factor is that this spectrum is not allocated solely to the Fixed Service. In fact, in many countries the Fixed Services have no access to this spectrum at all. A more detailed country-by-country breakdown follows. Please sign up below to receive the entire white paper.
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Trevor Burchell, Aviat VP of Middle East, Africa and Europe Sales and Services.
In a recent interview, Trevor Burchell, Aviat Networks VP for Middle East, Africa and Europe sales and services, commented on the recent trend of low latency microwave networks. Though increasingly found in the telecom infrastructure of financial institutions, low latency microwave is not limited to these applications, he says. Burchell sees its applicability in uses as diverse as health care, government and utilities.
Some considerations are common to all microwave networks—low latency and all others, according to Burchell. Proper path planning and network engineering must be executed in order to have the most fully functional wireless point-to-point backhaul possible, he says.
In general, Burchell sees microwave as the best choice where telecommunications have to be rolled out quickly and cost effectively. There are many other points to consider. The complete interview is available online in Engineering News.
IWCE 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!
Director Business Development
Ultra-long microwave links between backhaul towers enable long-distance telecommunications in the Mojave Desert. Photo credit: °Florian / Foter.com / 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.
For discussion purposes of ultra low latency, two theoretical ultra low latency microwave networks are compared to an existing optical Chicago-NY network.
In today’s ultra-competitive High Frequency Trading markets, speed is everything, and recently wireless technologies, and specifically microwave networking, have been recognized as a faster alternative to optical transport for ultra-low latency financial applications.
Even though microwave technology has been in use in telecommunications networks around the world for more than 50 years, new developments have optimized microwave products to drive down the latency performance to the point that microwave can significantly outperform fiber over long routes, for example between Chicago and New York. This has provided a new market opportunity for innovative service providers to venture into the microwave low latency business.
Although reducing the latency of the equipment is an important consideration, the most important metric is the end-to-end latency. Many factors that influence overall end-to-end latency require a deep understanding of the technology and how this is applied in practice.
This white paper will show that to achieve the lowest end-to-end latency with the highest possible reliability and network stability not only requires a microwave platform that supports cutting edge low latency performance but also a combination of experience and expertise necessary to design, deploy, support and operate a microwave transmission network.
(Photo credit: LittleJoe via Wikipedia)
Do not be Alarmed by this latest video in the Radio Head Technology Series (complimentary registration). For the insider’s perspective on Hot Standby, we will not keep you waiting. Dick Laine, Aviat Networks’ principal engineer, has many informed views on Diversity and relates them in his familiar relaxed presentation style.
All puns aside, Dick covers the multitude of options available in Diversity Schemes (and all their acronyms!). Plus, there is a lot to know about the differences in asymmetrical splitters for digital radios and their analog predecessors. Turns out there is no point in using symmetrical splitters in digital microwave radios. Even a heavily asymmetrical split provides as much protection as a symmetrical split but it avoids 2-3 dB in fade margin losses, providing significantly more uptime.
And if there is anything you need to know about Alarms, Dick takes a fine-toothed comb to the subject and teases out the details, providing context for the strategy of how they function in keeping your wireless communication network online. Dick will also tell you how improvement in digital radios has led to large gains in recovery time when radios in a Hot Standby arrangement are switched and quadrature relock can now essentially be avoided. On errorless switching, although it has greatly benefitted microwave radio usage, Dick will tell you the importance of early warning alarms to it.
So make no mistake, Dick is your information source for all things microwave radio—wrap your head around it!