If Microwave Didn’t Exist for Small Cells, We’d Have to Invent It!

FierceWireless-eBook-microwave-backhaul-being-reassessed-as-strategy-for-small-cell-LTE-traffic-aggregation-on-business-campuses

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.

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Aviat Advanced Microwave Networking Seminar: DC Style

Microwave Networking seminar hosted by Aviat Networks in Washington D.C. Sept 2012

The Microwave Networking seminar hosted by Aviat Networks in Washington D.C. in Sept 2012 had a large turnout of attendees who listened to speakers present on wireless security, MPLS, Carrier Ethernet and other topics of interest to the backhaul community.

Aviat Networks recently completed the latest in its Technology Seminar series on microwave networking with a two-day event in the Crystal City area of Washington D.C. One observer noted attendees were particularly interested in hearing more about security of wireless backhaul systems and how to make a choice between using IP/MPLS or Carrier Ethernet.

The seminar was packed to capacity with more than 100 attendees from organizations that included various federal government agencies, utility companies, public safety organizations and mobile operators. These seminars focus solely on issues relevant to microwave deployments, related technology, regulatory issues, and deployment considerations—with no product pitches.

Attendees took advantage of an agenda that covered a wide variety of technology topics, including microwave-focused sessions on capacity, Ethernet QoS and OAM, IP/MPLS, security and strategies for lowering the total cost ownership of microwave networking. The highlight of the seminar was again Dick Laine, longtime Aviat Networks principal engineer, who spoke at length about Microwave Path Engineering and designing links using Adaptive Modulation. Dick is one of the foremost authorities in the U.S. on microwave planning and path design, and some attendees travel long distances just to hear him speak and share his experiences of more than 50 years in the microwave networking business. (If you’ve never heard/seen Dick present, register for his free Radio Head Technology Series).

Aviat Networks also welcomed special guest speakers from the NTIA, Comsearch, CommScope, Tellabs and LTI DataComm who graciously contributed their time and effort to provide a deeper understanding for attendees on their topics of expertise.

Keep a lookout for details of the next Technology Seminar that may be coming to a city near you! Or if you would like to be notified directly when our next microwave networking seminar is scheduled, please complete this form.

Stuart D. Little
Director, Product Marketing
Aviat Networks

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Why Bigger is not Always Better for Mobile Backhaul!

Terrestrial microwave radio system with two an...

Terrestrial microwave radio system with two antennas employing space diversity. (Image via Wikipedia: Photo credit David Jordan)

Antenna gain is directly related to the size (diameter) of the antenna, and wireless transmission engineers looking for more system gain to improve link performance on long or tough paths in frequency bands below 10 GHz may resort to using very large antennas with diameters of 12 feet (3.7 m) or more. However, bigger is not always better. In fact, large antennas should only be used under the most unusual of circumstances.

Use of large, oversized antennas was commonplace during the 1960s and 1970s, for analog FM-FDM heterodyne microwave communication high-capacity links operating in the L6 GHz band. This was for good reason. Communications paths consisting of multiple radio links required very high receive signal levels, and fade margins of up to 50 dB, on each link to meet end-to-end noise objectives. The large antennas helped cut baseband thermal noise by more than 3 dB, which is half that of smaller antennas. Many of these paths were relatively short and many of these analog wireless links employed frequency diversity, so higher fade margins were needed to reduce outage—especially in N+1 hops. This reliance on large antennas is often still prevalent in the minds of many wireless transmission engineers.

Today’s Digital Microwave Systems

In contrast to old analog systems, digital microwave operates essentially error-free (i.e., with a bit error rate of 1 in 1,013 transmitted bits), even with much smaller fade margins. Adequate path clearance, optimal selection of diversity arrangements using smaller antennas and the precise alignment of antennas are far more effective to ensure that error performance objectives for microwave communications are met.

Big Antennas = High TCO

So because big antennas are not really needed to ensure high path availability, they do directly impact the total cost of deploying and operating a microwave link, namely:

  • Wind Loading—There is more wind loading because of the larger surface area. A 12-ft antenna has 45 percent more loading (e.g., 1,400 lbs wind load in a 70mph wind) compared to a 10-ft antenna (e.g., 980 lbs wind load). This means the microwave tower needs to be stronger to be less susceptible to the sway that results in antenna misalignment. Stronger towers mean more costly new towers, or expensive upgrades to existing towers
  • Beamwidth—Beamwidth of a 12-ft dish is 25 percent narrower compared to a 10-ft antenna, which further increases the tower’s rigidity requirements and thus cost
  • Non-Diversity vs. Diversity—Large 12-ft antennas are sometimes justified by assuming that the single large dish is more cost-effective and/or has performance characteristics as good as two smaller diversity dishes. A single 12-ft dish with its 1,400-lb single-point wind load—and narrower beamwidth—puts far more stress on a structure than dual 8-ft diversity dishes with a distributed wind load of 1,260 lbs (2x630lbs) and much wider beamwidths. Smaller diversity dish arrangements also increase the wireless link’s performance by reducing multipath outage by more than 80 percent compared to a single 12-ft dish deployed in a non-diversity hop
  • Antenna Decoupling and Alignment—The smaller beamwidth of larger antennas also increases the difficultly to align accurately, and the risk of antenna decoupling due to angle-of-arrival variations during nocturnal atmospheric (k-factor) changes. Antenna decoupling, directly proportional to path length, is increased on those longer paths in difficult geoclimatic areas that attract the use of 12-ft dishes. It can be a death spiral—the longer, more difficult paths that attract the use of larger, narrower beamwidth antennas are those that are even more sensitive to the resulting geoclimatic conditions!
  • Aesthetics—Bigger isn’t better when deploying dishes on towers, buildings and—especially—mountaintop sites, due to aesthetic concerns, building/tower owners’ concerns and local planning limitations. These can often be mitigated by using smaller antennas
  • Deployment Costs—The overall deployment cost differential between a single 10-ft and 12-ft antenna can exceed $10,000 when transport, installation and ancillary hardware are taken into consideration, and this does not include the potential cost of added tower strengthening and increased monthly tower lease charges

So before you consider using large 12-ft+ antennas, think again and consider the bigger picture. You may well end up spending a lot more money for a path that may perform more poorly than it would have if smaller antennas had been used.

For more tips, we’ve also included some wireless transmission engineering guidelines for antennas and other wireless equipment.

Stuart Little
Director of Corporate Marketing, Aviat Networks

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Fiber Isn’t Everything: Key Role of Microwave in Mobile Backhaul

Fiber

If fiber is this much of a mess in your wiring closet, just imagine the difficulty of deploying it to your cell site. Image by DrBacchus (Rich Bowen) via Flickr

Last year in August, Aviat Networks presented its argument for why fiber optics technology isn’t everything where backhaul of wireless networks is concerned. If anything, this point has only been reinforced by analyses and anecdotal stories showing that fiber can be overkill for the mobile backhaul requirements of  LTE wireless. Plus, there is the simple truth that fiber cannot be deployed to every cell site due to financial and topological issues. That’s why microwave technology remains the world’s first choice for backhauling wireless networks. So let’s look at last year’s FierceWireless webinar slide presentation and refresh our memories.

These slides present the findings of an Ovum survey of North America’s largest backhaul players to understand their strategies regarding media types used to supply cell-site backhaul.

Ovum found that demand for wireless backhaul equipment in North America will continue to grow as mobile operators upgrade their networks to support higher-speed LTE networking technologies. The most common backhaul strategy for mobile operators in the region comprises leasing services over fiber combined with owning and operating microwave-based facilities. Microwave has a distinct advantage vis-a-vis leased services over the long-term due to the opex associated with leasing.

If you would like to see more, you may register for the on-demand replay of the full webinar. It will also present the latest trends and advancements in microwave transmission technology that support the evolution of mobile backhaul networks to all-IP.

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Aviat Networks in the News: Highlights & What’s Ahead in Wireless

France Télécom phone booth in Wellington, New ...

Image via Wikipedia

This month we have a few technology updates from our travels abroad to London and Amsterdam where we presented our perspectives on backhaul at two LTE conferences.

In May, Stuart Little, our director of global corporate marketing, presented at an LTE backhaul conference organized by Telecom IQ in London. Stuart hosted a workshop that focused on the current challenges faced by mobile service providers while preparing their backhaul networks to meet the demand of next generation LTE broadband services. Comprising an intimate crowd of mostly operators, the conference focused on a series of operator presentations, panel discussions and roundtable conversations. Representatives from operators such as BT, Telenor, France Telecom, Telecom Italia, Vodafone, Mobitel and Saudi Telecom were in attendance. Some key issues discussed focused on the backhaul needs of LTE, which are difficult to predict. With a few exceptions, most LTE deployments to-date are limited or in the trial phase. Operators are also grappling with a mix of technologies in their networks, making migration to all-IP a huge and complicated task.

While in London, Stuart also spoke at the 13th annual Transport Networks for Mobile Operators (TNMO) Conference on May 10. TNMO is one of the largest conferences in Europe focused purely on backhaul transport networks. This year, Aviat Networks participated by presenting on the topic of “Realistic Capacity Requirements for LTE,” or why fiber is not the only answer, and took part in a panel discussion on Carrier Ethernet for mobile backhaul. The conference was fairly well attended, with a packed agenda that covered the full range of transport challenges from the access to the core. Numerous solutions to the problem of delivering more capacity to meet expected demand were discussed, including network sharing, microcells, network offload and intelligent backhaul optimization techniques. It seems that there is no single winner in the race to find a solution. Operators are going to have to choose from an array of options to get the right fit for their particular needs.

Over in Amsterdam, Peter Croy, our senior IP network architect, presented on the topic of Carrier Ethernet for LTE mobile backhaul requirements at the LTE World Summit. Not sure if you have read previous blogs or joined in our webinars on this subject, but Peter is a well versed expert on backhaul. See his overview from the conference.

With summer fast approaching and vacations looming, June will be a bit slower. Good thing as planning will begin for some major events and shows coming in the fall and early 2012.

An event you won’t want to miss is the 1588v2 Synchronization for Mobile Backhaul Networks Webinar on June 6. Hosted by Patrick Donegan, senior analyst at Heavy Reading. This webinar will bring together leading vendors and operators to develop best practice guidelines for operators as they deploy the 1588v2 standard. Drawing on real implementation case studies, industry leaders will demonstrate where some implementations have gone wrong in the past and what leading operators and vendors are now doing right to deploy this key standard. Please join us for this highly interactive webinar. The webinar is co-hosted by Errol Binda, our very own solutions marketing manager.

Another interesting event is the National Urban Areas Security Initiative Conference (UASI) conference held in San Francisco, June 20-23. This conference is in cooperation with Department of Homeland Security, Federal Emergency Management Agency and the Grants Programs Directorate. The conference will provide an opportunity for stakeholders from all areas of homeland security and emergency preparedness to gather and exchange important information to make the United States safer.

We will have a booth, No. 85 in the Continental Ballroom, at the conference where we will display our public safety solutions along with showcasing all-indoor configurations of Eclipse Packet Node. Ali Hirsa from Aviat Networks will be at the booth to answer any questions you may have.

That’s it for now. I will be back in touch next month to update you on the latest happenings at Aviat Networks. Until then, follow the dialogue and news on our social sites.

www.aviatnetworks.com

www.facebook.com/AviatNet

www.twitter.com/aviatnetworks

www.blog.aviatnetworks.com

www.youtube.com/aviatnetworks

Cyndy Johnson
Director of Corporate Communications, Aviat Networks

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Aviat Networks in the News: Recent Highlights and What’s Ahead

What do Orlando, Winnipeg, Rio de Janiero, Spokane and Santa Clara have in common? Nothing, except for the fact that they’re all on a list of places where we have been this past month visiting customers and participating in events. Unfortunately, I didn’t have the good fortune to go, but some of our top marketing and engineering team members did and had the chance to meet industry experts to share and exchange ideas and thoughts on microwave backhaul technology, trends and opportunities.

One of the major events we attended was CTIA Wireless Conference 2011, which was held March 22-24 in Orlando, FL. At the show, we participated in a panel discussion and presented on the latest trends in microwave radio technology at the Tower Technology Summit. In one of the sessions, Shaun McFall, our CMO, talked about the backhaul capacity requirements to support 4G/LTE cell site deployments. You can read his viewpoint on “Why Fiber is not the Answer for 4G/LTE Backhaul in North America.”

In addition, Gary Croke, our senior product marketing manager provide his insights on how microwave technology is well positioned to serve both the short and long haul backhaul needs for deploying next-generation cellular networks. You can read more about his viewpoint on his blog post.

And if that wasn’t enough, we announced our IEEE 1588v2 synchronization capability for mobile backhaul and co-promoted it with Symmetricom® as part of its SyncWorld Ecosystem Program. Find out more information about deploying IEEE 1588v2 Synchronization over Packet Microwave Networks.

Moving on to Canada, Gary gave a different presentation titled “Hybrid Radio and Essential Functionalities for Smart Grid” at the MIC/MUG 5 UTC Regional Conference in Winnipeg, Manitoba, Canada, on April 14. Attendees at the conference included utility radio engineers who were interested in learning about upgrading legacy TDM-based microwave systems and devices to meet the needs of Smart Grid. Gary’s presentation focused on hybrid radio, Strong Security, Adaptive Coding and Modulation, and improved capacity and performance—all features required to support the evolved Smart Grid utility network. Find out more about the Utilities Telecom Council.

Another great event that we participated in this month was the LTE Latin America 2011 Conference in Rio de Janiero. Unfortunately—again—I did not get a chance to go, but Louis Samara, our director of marketing/channel sales, Latin America, did attend and spoke on the importance of microwave backhaul for mobile operator migration to Long Term Evolution/4G. During the conference, he met with Emmanuel Jaffrot, asesor tecnologico del ministro de planificacion federal, Argentina, Humberto Roca, CTO ANTEL, Uruguay, and Juan Carlos Pepe, general manager Telecom Personal Paraguay to discuss several telecommunications initiatives. Check out our Flickr site to see the photos and get additional details on our visit.

Another interesting event was the WiMAX Rural Operators Summit, organized by the WiMAX Forum and held in Spokane, WA, April 26. Stuart Little, our hip, savvy, director of marketing, attended the event, which was the first event of its kind organized by the forum in the US. It drew good attendance from operators and vendors, including a few international attendees. The agenda covered a variety of topics of concern for smaller operators who are deploying wireless networks to bring broadband services to the unserved and underserved rural communities in the US.

Speaker panels included larger operators such as Sprint and Clearwire, as well as smaller ones like Ecliptixnet Broadband and Keyon Communications, with some interesting debates including how operators are navigating the challenging process of winning and utilizing federal Broadband Stimulus funds. Probably the biggest challenge that these rural operators have is access to capital to invest in their networks. Of course, stimulus grants help, if you’re one of the lucky ones to win an award. For the rest, cost is a huge driver for their equipment selection. On the WiMAX side, specific requirements such as frequency bands for the US (e.g., 3.65 GHz) make it difficult for them to deploy a WiMAX basestation to serve customers in very small rural communities, since vendors struggle to achieve economies of scale to drive prices down far enough.

On the backhaul side, focus is also on cost, not so much on capacity. Many operators utilize very cost effective unlicensed microwave solutions for backhaul, but to support a real “carrier-grade” network licensed microwave is preferred to enable the high reliability and interference free operation. Stuart sat on a panel with three representatives from other independent microwave companies, where we discussed how we as an industry are bringing new solutions to lower the cost of ownership of licensed microwave for rural operators. New techniques, such as ACM and ring network topologies can help to reduce antenna sizes, one of the largest OPEX drivers. Some of the proposals now presented to the FCC will also help rural microwave deployment, including reducing restrictions on minimum antenna size and bandwidth efficiency in the lower frequency bands.

Whew! That was a lot of detail, but worth the trip to Spokane.

Now onto the one of the coolest events, which will be broadcast tomorrow, the “LTE Backhaul Capacity Requirements: Diving Deeper” webinar. Panelists will include Stuart and Peter Croy, senior IP network architect for Aviat Networks, in addition to other industry experts.

Following on from our previous webinar where Stuart and Peter addressed the practical backhaul capacity requirements of 4G/LTE, this webinar discussion will dive deeper into our analysis, share some new insights, provide updates on operators’ plans regarding backhaul and discuss how the emerging small cell market will address network capacity needs and what new backhaul innovations will be needed for these small cells. Please join us for this highly interactive webinar to delve further into the network capacity requirements for LTE backhaul.

So what’s ahead for next month? Well, it will be busy. So many interesting events and topics!

LTE Backhaul Conference, London, May 3-6

London is our first stop. Although just after the fanfare of the Royal Wedding—which by the way would have been nice to see in person! But LTE backhaul is “just” as exciting. At the LTE Backhaul Conference in London on May 3-6, we will host a workshop on “IP Mobile Migration Challenges and Issues.” If you live in the UK or will be in London, we invite you to join us alongside mobile operators and industry partners to tackle some real-world issues related to IP backhaul migration, including planning for realistic LTE capacity demands and packet synchronization migration, in this engaging and interactive workshop. Details about the conference.

Transport Networks for Mobile Operators Conference, London, May 10

While in London, Stuart will also speak at the 13th Annual Transport Networks For Mobile Operators Conference on May 10. Stuart’s topic will focus on “A Realistic Look at LTE Backhaul Capacity.” Find out more about the conference.

UTC Telecom, Long Beach, CA, May 10-13

At this conference, Gary will speak on the topic of “Microwave Technology Options.” In his session, he will give an overview of the microwave options and applications best suited to each form in a side-by-side comparison that will enable you to develop your microwave plan for the future. Find out more about this conference.

LTE World Summit 2011, Amsterdam, Netherlands, May 17-18

Peter will speak on the topic of “Examining the Role of Carrier Ethernet in Meeting Mobile Backhaul Capacity Needs Including LTE.” View the conference details.

And find out more about our other events!

That’s it for now. I will be back in touch next month to update you on the latest happenings at Aviat Networks. Until then, follow the dialogue and news on our social sites.

www.aviatnetworks.com

www.twitter.com/aviatnetworks

www.blog.aviatnetworks.com

www.youtube.com/aviatnetworks

Cyndy Johnson

Director of Corporate Communications, Aviat Networks

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Taking a Realistic Look at 4G Backhaul Needs

Let’s get past the hype.

We can get a good idea of what capacities 4G networks will need for backhaul we should look at what the technology is actually able to support.

The backhaul requirements for a single cell are fixed by a number of factors, regardless of how many users there are in that cell. Network congestion and frequency interference will limit the throughput achievable to rates well below the advertised peak rates.

For a typical three sector macro cell operating in the maximum 20MHz channel bandwidth, the total backhaul capacity needed is actually below 200 Mbit/s, even with the future introduction of LTE Advanced (Release 10).

For the current Release 8 of LTE now being deployed, and with smaller operating channels of 5 or 10 MHz, the actual backhaul capacity needs will be more often in the 10’s of Mbit/s, not the 100’s!

So if this is the case, why do you need fiber?? It’s pretty clear that the presumption that only fiber is suitable for 4G backhaul doesn’t make much sense! As shown by Figure 1, modern microwave transmission systems more than meet the capacity needs of 4G/LTE, with lots of room to spare.

Microwave supports more than enough backhaul capacity for 4G/LTE

Innovative new microwave technologies have been introduced to the market in the past few years that dramatically increase the throughput capacity, while the move to packet-based transport has also enabled a new range of Ethernet/IP-aware products that are able to intelligently utilize the available microwave backhaul spectrum better than ever before, with throughputs of 1 Gbit/s achievable with fiber-like reliability.

Apart from that, the average cost of microwave has continued to decrease over the years. The result is that microwave $/MBit is a fraction of what it was just 5 years ago.

Why Pay for Capacity That You Don’t Need?

Driven by this continued uncertainty, many operators could waste huge amounts of money by deploying fiber to cell-sites that can be served much more economically with proven microwave solutions.

So far from fiber being the only answer for operators deploying HSPA+ & LTE, microwave transport can and will meet the capacity needs for mobile backhaul for many years to come.

Stuart Little

Director of Marketing, Aviat Networks

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Time for a Backhaul Reality Check

The introduction of new high-speed 4G mobile technologies is gathering pace, but there are indications that many operators still do not have a clear understanding of what impact this will have on their backhaul networks. With the forecasted demise of copper-based backhaul in U.S. networks, operators are faced with the critical decision between deploying either fiber or microwave to the cell-site.

The problem lies in the uncertainty surrounding what the true future capacity needs for 4G/LTE will be. Misreading this requirement could ultimately lead to over-building backhaul capacity, resulting in the waste of enormous amounts of network investments; money that instead could be put into more substantive ways of increasing network capacity, such as investing in new spectrum.

Driven by this uncertainty, operators risk making commitments that lock in the high lifecycle costs of building or leasing fiber – costs that far exceed that of a typical microwave connection. In reality, deploying fiber to the cellsite due to concerns about running out of backhaul capacity is a significant overkill. Based upon the 4G technologies and deployment scenarios, it is possible to predict what the maximum backhaul needs for 4G sites will be, meaning that in many cases operators can avoid a budget burden that they must live with for years to come.

So when it comes to backhaul need for 4G what is needed is a “dose of reality,” that then enables optimal backhaul network planning that balances realistic capacity expectations with total cost.

Check back for the second part of this post next week, when I take a look at some of the things that are driving this uncertainty.

Stuart Little

Director of Marketing, Aviat Networks

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