Posted by: aviatnetworks | June 27, 2015

Getting Schooled: 5 Reasons to use Class 4 Antennas

Class 4 antennas helped reduce interference due to congestion for 3 sites in South America

As mobile phone and other wireless networks “densify” in the parlance of the day, airwave congestion will inevitably rise causing greater interference. Generally, microwave path planners will use dish antennas that provide tighter radiation patterns with more focused main beams and smaller side lobes to overcome interference that results from congestion.

To indicate the tightness of their radiation patterns ETSI (European Telecommunications Standards Institute) classifies antennas from 1 to 4 with higher classifications having tighter radiation patterns. Until recently, to fight interference in most circumstances wireless transmission engineers would resort to Class 3 antennas for deployment scenarios where “very high interference potential” existed.

However, the situation has changed. More drastic implementation scenarios now drive path planners to invoke more dramatic solutions. That includes use of Class 4 antennas, which are for “extremely high interference potential” situations, according to ETSI. For a more detailed treatment of antenna classifications and radiation patterns, see the ETSI document “Fixed Radio Systems; Point to Point Antennas.”

It’s an urban thing
In most cases, microwave radio congestion that leads to interference problems occurs primarily in urban locations. With wireless backhaul sites in much closer proximity in urban areas than in rural or suburban locales, there it’s more likely that side lobes from microwave transmitters could become sources of secondary RF radiation, which can overlap with point-to-point links between neighboring sites.

For example, according to an Aviat Networks analysis of three wireless sites in South America that recently experienced interference issues, at one site the congestion was so intense as to make one complete channel unusable. Even if Class 3 antennas were used, the interference levels were too high to be able to reactivate the disabled microwave channel.

Wider channels, larger capacity
For situations where the operator needs to increase capacity from a wireless backhaul site, the easiest way remains widening the channel size. But at sites that experience extremely high interference, the operator may not be able to coordinate radio frequency pairs in wide channels with Class 3 antennas. However, moving up to Class 4 antennas would allow the operator to optimize the signal-to-noise ratio and let higher modulations come into play, so wide channels could be coordinated with correspondingly higher data rates.

Smaller is more
In cases of high interference, larger antennas can be used to reduce it. For a subset, smaller Class 4 antennas can be used instead of their oversize Class 3 counterparts. Thus, operators who deploy Class 4 antennas gain the added benefit of dropping down a parabolic dish antenna size as compared to a Class 3 antenna in the same application. In general, smaller dishes advantage the operator due to their lighter weight and lower opex tower charges, albeit with an initially bigger upfront capex. Because Class 4 antennas represent an elevated level of precision tooling and more detailed manufacturing versus lower class antennas, capex of these passive, higher-performance infrastructure pieces always weighs in the balance.

Other considerations
As we’ve seen, Class 4 microwave antennas have many general uses. They also are very good alternative solutions for specific industries. For example, utilities often find it difficult to implement Adaptive Coding and Modulation schemes in their backhauls, so Class 4 antennas can provide another way for them to achieve their connectivity and capacity goals.

Lower frequency bands (i.e., less than 11 GHz) have long had access to Class 4 antennas. More recently, antenna manufacturers such as Commscope have begun to make Class 4 antennas for higher frequency bands (e.g., 13, 15, 18, 23 GHz). And RFS has also expressed interest in supplying higher frequency class 4 antennas.

This overview has provided a broad grounding in Class 4 microwave antenna subject matter, but for more in-depth information please download the Aviat white paper “Use of Class 4 Antennas” for which no signup is necessary.

Posted by: aviatnetworks | June 26, 2015

3 Ways to Get Smart About Nodal Microwave

Choose Aviat Smart Microwave NodesAt a time in the not-so-distant past, there was only one way to implement microwave radio: one radio link per microwave terminal. Did not matter what type of link it concerned: protected, non-protected or multi-channel. From the advent of digital microwave radio in the 1980s and 1990s, terminals typically had no options for integration of co-located telecom devices. And to interconnect muxes or switches required external cabling and possibly a patch-panel.

Then in the early 2000s, so-called “nodal” radios came into vogue. Designed to address the drawbacks of the one-radio-one-link paradigm, a single microwave radio node could serve as a platform for multiple links. There were still limitations when it came to radio and switch interactions, but multiple sources of traffic could now be integrated and connected on the nodal platform.

For approximately the last 10 years, nodal microwave radios have been Carrier Ethernet (CE) capable with full integration between radio and Ethernet switch. In addition, Layer 3 IP/MPLS capability has become more prevalent, which, together with CE, enables nodal microwave platforms to assume switching functionality.

Terminal redux
Since 2011, a movement’s been afoot and gaining momentum to bring back the one-link-per-radio terminal model. That’s not the overt objective of industry participants but the collateral effect of unintended consequences. The real goal of various microwave practitioners has been to bring forth a new low-cost concept of all-outdoor radios (ODRs). Designed as all-Ethernet/IP radios, these newest ODRs were supposed to be an easy-to-install, price-conscious alternative to traditional split-mount radio setups. These high-capacity outdoor units should have supplanted split-mounts and swept away all memory of more than 20 years of microwave market dominance.

However, the mobile backhaul market still has an abundance of TDM-only dependent 2G and 3G base stations in the installed base. And all-IP ODRs cannot support circuit-based traffic without separate adapters that must be mounted indoors. Other issues regarding power management, reliability, maintenance, aggregation and complex configurations also dog ODRs.

Layer 3 IP/MPLS enters the backhaul
As mobile phone networks have gone up the speed and capacity curves, with LTE and LTE Advanced pushing the 4G envelope, the old ways of wireless architecture don’t completely suffice anymore. With this demand for more speed and capacity from the mobile network, the mobile backhaul needs to supply a more robust solution to support 4G wireless. For business purposes, Layer 3 IP/MPLS proves to be the best answer for aggregation and edge sites.

By having IP/MPLS at the cell site, the delivery of new services accelerates. But introducing discrete IP routers into the cell site has its own considerations to take into account.

Of course, the easiest and most convenient approach to implementing IP/MPLS at the cell site is to just deploy a standalone cell site router (CSR) alongside the existing split-mount microwave radio. Though intuitively appealing, this approach has several drawbacks such as:

  • Added cost/space requirements
  • Demarcation issues
  • Management complexity
  • Lack of design with microwave in mind

Even in the new ODR model, implementing IP/MPLS at the cell site faces challenges. While designed specifically to be “plugged” into an IP router, ODR Ethernet radios have the same limitations of traditional split-mount radios in these networking configurations. In addition, ODRs must contend with:

  • Microwave configuration complexity
  • Poor performance (i.e., no media awareness)
  • Lower reliability
  • Complex power management

Smart microwave nodes
So with the traditional split-mount radio and new-fangled all-outdoor radio implementation scenarios for instituting IP/MPLS functionality both being less than ideal, what is the smart thing to do? Aviat Networks has come up with a concept called “smart microwave nodes” wherein the uniquely integrated family of CTR 8000 microwave routers is capable of pairing with split-mount, all-outdoor, all-indoor, microwave, millimeter wave, IF or Ethernet radios within a single IP address.

Managed by the ProVision network management system, an Aviat smart microwave node can function as one element in the network while supplying optimal performance for microwave and IP. To find out more, download the “Why Choose Smart Microwave?” white paper—no signup necessary.

At the Ghana Telecom Awards in May 2015. Ahmed Adama, Aviat Ghana country manager (right) proudly accepts on behalf of all Aviat Networks the honor for  Best Microwave Backhaul Vendor of 2015.

At the Ghana Telecom Awards in May 2015, Ahmed Adama, Aviat Ghana country manager (right) proudly accepts on behalf of all Aviat Networks the honor for Best Microwave Backhaul Vendor of 2015.

At the recently concluded Ghana Telecom Awards held in May 2015, Aviat Networks won the Microwave Backhaul Vendor award for the second year in a row. Based on a survey of telecom industry participants, Aviat bested all the other major microwave specialists and one of the top three telecom generalists.

“I am very proud to inform you that Aviat Networks has been honored again as the best overall microwave backhaul solutions provider in Ghana,” said Ahmed Adama, country manager, Ghana, Aviat Networks. “The combination of our microwave networking technology and full turnkey service capability was key to securing this award.”

Aviat Networks: Ghana Telecom Awards Microwave Backhaul Vendor award winner for 2015.

Aviat Networks: Ghana Telecom Awards Microwave Backhaul Vendor of the Year for 2015.

Aviat Networks won the microwave backhaul award based on the votes of operators for favored solutions vendors and informed opinions of industry experts. According to MobileWorld Magazine, the winner of this category recognizes the need to have a core focus on providing microwave networking solutions to customers in the telecom industry as well as industry leadership, including depth and breadth of services.

“We warmly congratulate all those honored today,” said Akin Naphtal, group publisher of MobileWorld Magazine, organizer of the Ghana Telecom Awards. “It is an incredible achievement to be announced as an award winner today, as the high-caliber of nominees is a true reflection of the dynamic, creative and inventive thinking that will drive our industry in the following years.”

Now in its fifth year, the Ghana Telecom Awards is designed to celebrate the continued growth and success of the ICT marketplace and focus on the exceptional and innovative performers within the industry. They are designed to reward and recognize not only the products and diverse innovations that keep the ICT sector exciting but also the companies and people who make the industry great, according to MobileWorld.

The awards have become the benchmark for outstanding performances throughout the industry and symbol of excellence to mark leadership, quality and innovation among ICT players, according to the publisher.

Look for Aviat’s new circular celebrating the back-to-back awards in West Africa. Or preview the content now.

Posted by: aviatnetworks | May 22, 2015

Telecom Industry Participants call on FCC for E-band Action

While U.S. regulators decide on flat-panel antenna rules for E-band, operators and subscribers walk a tightrope of red tape.

While U.S. regulators decide on flat-panel antenna rules for E-band, operators and subscribers walk a tightrope of red tape.

Back in April the telecom experts over at CommLawBlog weighed in on a simmering issue in the 70-80GHz radio space. Since October 2012, the Federal Communications Commission (FCC) has mulled over a motion by the Fixed Wireless Communications Coalition (FWCC) to relax rules for flat panel antennas as well as a 2013 waiver to the existing rules while it considers a new rulemaking.

Lack of taking any action on any of these filings has left the backhaul industry in a quandary. With viable radio solutions ready to deploy in the 70-80 GHz frequency ranges, the only holdup has been a technical requirement that FCC rules place on the radiation pattern of the very thinnest of flat panel antennas. These rules were originally formulated for an era where microwave radios were used for links that spanned 1 to 5 kilometers.

In the new urban reality for small cells, the distances between mobile base stations will be measured in hundreds of meters. At these lengths, the radiation patterns of flat panel antennas will not materially increase interference, to paraphrase language the FCC itself has used previously when approving use of smaller antennas in the 6, 18 and 23 GHz bands, circa 2012.

With small cell wireless in close-in city settings, both mobile and non-mobile subscribers have a heightened sense of awareness, and they will take extra notice of backhaul radios with prominent parabolic dishes that stick out like sore thumbs. With their figurative and literal low profiles, flat panel antennas provide the critical missing link in ameliorating the aesthetics concerns that many feel toward old, bulky microwave installs. While these hulking communications devices were fine on towers at long haul sites way out by the interstate freeway or high atop skyscrapers in the heart of the business district, when they are situated on the side of a residential building the modern-day urbanite will not tolerate these telecom equipment eyesores.

In reality, there is very little for the FCC to decide upon. While the telecom regulator here in the United States has its own rules, regulators in much of the rest of the world use the ETSI standards. Actually, the standard in effect is of little consequence. The point of fact is that the flat panel antennas in question before the FCC have been approved for use in all these ETSI countries without any significant drawbacks being reported in nearly three years of use. Even the FCC’s companion agency to the north, Industry Canada, has given tentative go-ahead to flat panel antennas for use with 70-80GHz backhaul radios, with the implicit understanding that they will receive formal approval if no unforeseen snags occur in final rule drafting.

So while the rest of the small cell community enjoys a flat panel world, the U.S. is walking a tightrope of red tape in hopes that some decision is made—soon.

Full disclosure: Aviat Networks is the filer of the 2013 waiver request and is a member of the Fixed Wireless Communications Coalition. Aviat Networks is legally represented by Fletcher, Heald & Hildreth, PLC, the host of CommLawBlog.

Posted by: aviatnetworks | March 30, 2015

Layer 3 intelligence: cell sites need more than dumb pipes

Artificial Intelligence. Photo credit: miuenski / Foter / CC BY-NC-SA

Artificial Intelligence. Photo credit: miuenski / Foter / CC BY-NC-SA

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.

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