Microwave backhaul is being reassessed as a strategy for small cell LTE traffic aggregation on business campuses. Photo credit: cbmd / Foter.com / CC BY-NC-ND
Small cells get all the press! As LTE rolls out in networks on every continent except Antarctica, small cells are grabbing headlines in technology trades and geek fan-boy blogs across the Internet. They’ll be needed sooner or later to provide LTE access in all those places around corners of buildings on business campuses, in urban parks surrounded by concrete canyons and other inaccessible locations. But little or only passing thought is paid to the ways in which small cell traffic will be aggregated back to the main network.
However, in a new FierceWireless ebook, microwave backhaul is pointed out as one of the critical strategies to provide throughput for all the small cell traffic to come. Microwave was here before small cell. And it’s such a good fit for small cell, if it had not already existed, we’d have to invent it now! Our director of product marketing, Stuart Little, tells FierceWireless that microwave meets the capacity needs of LTE backhaul. And Fierce adds modern microwave technology is changing the perceptions of its use for small cell backhaul.
Neither sleet nor rain nor changing K factors at night will stop microwave from small cell service. Specifically, Little tells Fierce that rain has little to no effect on microwave at the lower frequencies, and where it does have some effect in the higher bands, different technical techniques can help mitigate it. To find out more about small cell microwave backhaul, we recommend any of the Aviat blogs and related articles below. Or just read the FierceWireless ebook.
- June 10, 2013
- Aviat Networks, backhaul, Capital expenditure, Denver, FirstNet, microwave, public safety, public safety communications, public safety community, public safety network
In the effort to build out the nationwide Public Safety Broadband Network, stakeholders are making themselves heard. They were heard at the Public Safety Broadband Stakeholder Conference held last week, June 4-6, 2013, outside of Denver, Colo., hosted by the Public Safety Communications Research lab. It brought to the surface the many competing agendas local public safety network operators, the First Responder Network Authority (FirstNet), wired and wireless vendors and even mobile app developers contend with.
Aviat Networks had a chance to sit down with Tammy Parker, editor of FierceBroadbandWireless, during the conference to discuss some of these issues, such as the debate on the effectiveness of fiber optic technology in backhauling public safety networks. The fact is that microwave indeed will be a key element in the design and implementation of the FirstNet mission-critical network. And fiber does not provide the reliability and survivability needed. In the commercial mobile telecom space, the poor survivability of fiber is tolerated, but when it comes down to crunch time when lives are on the line, public safety operators will take microwave over leased fiber.
Randy Jenkins, Aviat director of business development, expanded on this vital decision for public safety operators to make between microwave and fiber. “As a vendor vested in the public safety community for more than 50 years, Aviat understands its responsibility to find innovative ways of offering microwave solutions that can save CAPEX and OPEX in support of the biggest challenge FirstNet is addressing—not enough money. Aviat is bringing backhaul innovation to this program.”
The bottom line is that backhaul is always the bottleneck in any network planning. In that case, it’s important for public safety operators to address that aspect first, according to Tony Ljubicich, Aviat’s vice president of sales and services.
If you would like to hear more about how Aviat Networks is making microwave backhaul the best choice for FirstNet-ready public safety, leave your contact information and reference the upcoming webinar on public safety broadband backhaul for a major statewide network. We’ll let you know when it’s scheduled.
FirstNet is facing technological challenges as it careens toward key decisions for the Nationwide Public Safety Broadband Network. That was the key takeaway when APCO held its Public Safety Broadband Summit in Washington D.C., May 13-14. In that context, backhaul continues to be a hot topic. Typically more of an afterthought in commercial telecom systems, backhaul becomes the 900-pound gorilla in the room when defining high reliability telecom networks such as mission-critical public safety networks. This is due to the extremely high cost of fiber—CAPEX for new runs and OPEX for leasing—as well as its proven lack of survivability in worst-case scenarios.
For example, during Superstorm Sandy, 25 percent of all affected commercial mobile sites were down, and most had to be propped up by temporary microwave radio backhaul solutions due to the lengthy time needed to replace the damaged fiber. Chief Dowd of NYPD provided insight into the situation stating that the network’s reliability is defined during worst-case conditions, not during sunny days.
Aviat Networks’ APCO presentation, below, from the Broadband Summit dives deeper into these issues:
Or we can talk to you directly about your concerns for your mission-critical Public Safety network requirements.
Director, Business Development
- May 24, 2013
- backhaul, Cellular network, CRAN, CTIA, DAS, Distributed antenna system, FirstNet, LTE, public safety, small cell
CTIA: The Wireless Association held its annual show in Las Vegas, May 21-23. Photo credit: @jbtaylor / Foter.com / CC BY
This week, Aviat Networks participated in the very well attended CTIA 2013 wireless and mobile trade show in Las Vegas. The theme for this year’s event was “THE Mobile Marketplace” with various areas of focus dealing with applications, devices and, of course, infrastructure. LTE, backhaul and small cells were once again important infrastructure-related topics during the event.
Aviat was a Platinum Sponsor of the Tower & Small Cell Summit—a sub-conference program composed of presentations, panels and case studies on wireless backhaul, mobile video, Distributed Antenna Systems (DAS), small cells, 4G and residential tower builds. I spoke on a panel at this event and shared our views on small cell evolution, including our thoughts on the migration of the mobile network to the Cloud Radio Access Network (C-RAN) architecture—if interested in this topic, please register for our upcoming webinars: North America or Europe, Middle East, Africa.
In addition, this show also paid significant attention to FirstNet—the nationwide public safety LTE network here in the United States. Aviat’s Ronil Prasad shared Aviat’s perspective on FirstNet, options for network sharing to reduce costs and best practices for building mission-critical backhaul networks for public safety LTE (with our 60-year history in public safety and our deployments in some of the largest LTE networks in the world, we are uniquely qualified to talk on this topic).
In addition, Aviat’s meeting facility experienced a constant flow of customers, industry analysts and partners, which kept Aviat staff on its toes for the entire event. Overall, it was a great show and Aviat was happy to participate to share our views on some of the most exciting new topics in mobile networks in the U.S.
Director, Marketing and Communications
Many wireless operators, such as MTN in Ghana, need to optimize management of their networks and Aviat can help with products, services and software capabilities. Photo credit: Rachel Strohm / Foter.com / CC BY-ND
Wireless backhaul operators, both mobile phone networks and others carrying dedicated traffic, face the constant issue of maximizing the functionality of their systems.
In the emerging markets around the world, the pressure can be most intense. Wireless network reliability, availability and capacity all need to be increased. Customer expectations are on the rise, and operators must take the appropriate steps to meet and exceed them.
In working with MTN Ghana, Aviat Networks recently completed an implementation to increase network visibility (i.e., intelligence) by close to one-third. Aviat’s professional services experts designed the mobile operator’s backhaul links for high capacity and resiliency. Using ProVision, Aviat’s leading network management software, MTN Ghana can now administer its wireless backhaul efficiently and effectively with a reduced level of manpower.
Unless you want to return to payphones, cellular technology requires cooperatively licensed microwave backhaul to function properly. Photo credit: UggBoy / Foter.com / CC BY
Competitive licensing of fixed microwave backhaul bandwidth is a bad idea. And it should not go any further. The reasons why are laid bare in a new article in IEEE Spectrum by former electrical engineer and current telecom law firm partner Mitchell Lazarus. In general, he argues against federal spectrum auctions for microwave frequencies, and in particular for fixed microwave links. Undoubtedly, readers are familiar with the large cash bounties governments around the world have netted from competitive bidding on cellular bandwidth—first 3G and now 4G. An inference can be drawn from Lazarus’ article that some governments (i.e., the United States, the United Kingdom) had in mind a similar, if perhaps smaller, revenue enhancement through competitive auctions of microwave channels.
The problem lies in the fallacious thinking that operating fixed point-to-point wireless backhaul bandwidth is comparable to that of mobile spectrum. Whereas mobile spectrum license holders can expect to mostly—if not fully—use the frequencies for which they have paid top dollar, the same has not historically been true of license holders of microwave backhaul bandwidth. In most cases, mobile license holders have a virtual monopoly for their frequencies on a national, or at least regional, basis. Their base stations send and receive cellular phone signals omnidirectionally. They expect throughput from any and all places. So they have paid a premium to make sure no competitors are on their wavelengths causing interference.
On the other hand, U.S. holders of microwave backhaul licenses have specific destinations in mind for the operation of their point-to-point wireless networks. They only need to communicate between proverbial Points A and B. And, historically, they have only sought licenses to operate in their particular bandwidth on a particular route. They had no need to occupy all of their licensed frequency everywhere. That would be a waste. They just have to make sure they have a clear signal for the transmission paths they plan to use. To do that, before licensing, they would collaborate with other microwave users in the vicinity and a frequency-coordination firm to establish an interference-free path plan. Any conceivable network issues would usually be resolved at this stage prior to seeking a license from the Federal Communications Commission. Essentially, the FCC is just a glorified scorekeeper for fixed microwave services, passively maintaining its transmitter location license database.
But starting in 1998, with dollar signs in their eyes, governmental spectrum auctioneers started to sell off microwave frequencies in block licenses. The need for fixed microwave wireless services then was growing and has only grown fiercer with each additional iPhone and iPad that has been activated. However, access device throughput demand on one side of a base station does not necessarily fully translate all the way to the backhaul. Lazarus points out the example of now defunct FiberTower and its failure to make block microwave licenses work economically. After buying national block microwave backhaul licenses at 24 and 39 GHz, Lazarus notes, the firm resold the frequencies to Sprint and a county 911 emergency network operator. But those were the only customers. Lacking a robust enough utilization of its licensed backhaul frequencies, FiberTower had several hundred of its licenses revoked by the FCC and was forced into bankruptcy November 2012.
Subsequent auctions have attracted far fewer bidders and generated much less income for the Treasury Department. Much bandwidth has lain fallow as a result. And infrastructure buildout has stagnated.
Regulators should return the microwave backhaul licensing process to that of letting wireless transmission engineers cooperate informally among themselves, with the help of frequency-coordination firms, to arrive at fixed point-to-point wireless plans in the public interest. These are then submitted only for maintenance by the FCC or other regulators for traditionally nominal license fees—currently $470 per transmitter site for 10 years in the U.S., per Lazarus.
Forget the quixotic quest for chimerical hard currency. The commonweal demands it. You should demand it of the regulators—you can still give input regarding this scheme in some jurisdictions where it is under consideration. Clearly, the most efficient use of spectrum is to make it openly available to all because it means that every scrap of commercially useful spectrum is picked clean. We welcome your comments pro or con.
- April 5, 2013
- analog microwave, Aviat Networks, backhaul, Beatles, Canada, cutting edge technology, Dan Aykroyd, Farinon, John Belushi, John Lennon, Microwave transmission, MTBF, Nova Scotia, pac man fever, Ronald Reagan, Soviet Union
John Lennon was still alive when Aviat’s oldest microwave link first went operational in 1980. Photo credit: Roy Kerwood / Foter.com / CC BY
The year was 1980. The Americans beat the Russians for the Olympic gold medal in hockey. John Lennon of The Beatles was killed. Mount St. Helens erupted. The Soviet Union had just invaded Afghanistan. Ronald Reagan was elected president. The hostages were still in Iran. People asked themselves, “Who shot J.R.?” and caught Pac-Man fever. Voyager 1 flew by Saturn and left the solar system. The Empire struck back. John Belushi and Dan Aykroyd were on a “mission from God.” The Clash came calling on London. Led Zeppelin broke up. And Farinon Electric, Aviat Networks’ direct predecessor, put into service a series of analog microwave radio hops for the Canadian province of Nova Scotia’s Department of Natural Resources. The radios in question were the SS2000 model.
The province used them to carry government data traffic for firefighters and police, where data bits were stuffed into 4kHz voice channels. Remarkably, 33 years later, three hops of these SS2000 radios are still in operation, making these, quite possibly, the world’s oldest continuously in-service microwave links.
Farinon SS2000 analog microwave radio transmitters (but not entire units) were available for sale on eBay as recently as 2011! How’s that for longevity?!
Offering 120, 300 or 600 voice channels on the old 2GHz band, SS2000 radios were considered cutting-edge technology at the time—check out their cool retro-style data sheet—and highly reliable with their ability to provide microwave links despite the challenging weather and difficult propagation conditions of Nova Scotia—snow, ice, sleet, fog…they have it all! As proof, four other SS2000 radio hops were recently decommissioned and found to still be working up to spec as per the original, accepted level of performance. Then there was someone selling SS2000 radios on eBay in 2011!
But we challenge you, our loyal blog readers, to tell us of any even older microwave links that have been in operation for more than 33 years. So if you have an Aviat Networks link, or that from a predecessor company, which is still operating today and was installed before 1980, please comment! We want to hear from you!
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.
Spectrum above 6 GHz is much more available for small cell backhaul than spectrum below 6 GHz.
A different solution to handle the burgeoning demand for mobile broadband capacity will be needed. More spectrum coupled with more spectral efficiency will not be sufficient. A clear solution is more sites, but deploying more macro-sites in urban and dense urban areas (where most of the traffic will be needed) will not be feasible.
Small cells promise a new “underlay” of outdoor and indoor, low power micro-cells that are deployed on public and private infrastructure within the urban clutter, are seen as seen as a likely solution. Sites being considered include:
- Pole tops (e.g., such as street lighting, traffic light systems, electric utility poles, telco poles)
- Bus stops
- Building walls
- Building rooftops
These new sites will need to be compact, simple to install, energy efficient and incorporate an organically scalable and tightly integrated backhaul solution. As a result, there will be many more sites—some projections estimate that up to 10 small cells will be deployed for every macro-site. Small cells hold out the promise of great gains for the end users but massive challenges for the operators.
Small cell deployments so far have mainly been concentrated in Europe (3G) and the USA (LTE). 3G small cells may also be deployed in other regions as a means to avoid the difficulties in obtaining planning approval for larger macro-cell sites.
It’s Still Early
Today, as far as wireless small cell backhaul (SCBH) solutions are concerned, there is evidence of product immaturity and hyperactivity in equal measure.
There is profusion of aggressively hyped solutions, including many that are a rehashing existing/niche solutions and at the opposite extreme some very new and unproven technologies. In practice, these solutions are jockeying for position while operators grapple to understand the formidable planning and infrastructure challenges being thrown up by their small cell ambitions. It is apparent that few appear that they will fully satisfy the anticipated and emerging requirements in terms of performance (i.e., capacity, latency, availability), size/shape, ease of deployment and most importantly, total cost of ownership. For the complete article, download the PDF.
Stuart D. Little
Director, Product Marketing
- November 30, 2012
- Apple, Asia, backhaul, Code division multiple access, iPhone, Japan, Korea, LTE, mobile research, technology, Yankee Group
Back in October, mobile research firm Yankee Group held a very interesting webinar on the state of LTE around the world. The webinar, still available in replay, notes that, with the exceptions of Japan and Korea, North America is very far ahead of the rest of the world when it comes to implementing LTE. The LTE vanguard is based on North America, Japan and Korea having the greatest CDMA legacy.
Yankee Group analysts note the commonly known LTE driver in the form of worldwide proliferation of the iPhone and other smartphones has led to greater demand for high-speed connectivity. Overall, the webinar explores the LTE landscape from Asia to Europe to North America.