Mt. Otto: 11,000-foot Microwave Site Install in Papua New Guinea

Aviat Networks and its partners Kordia and Eltek installed an entirely off-the-grid microwave repeater and spur atop 11,000-foot Mt. Otto in Papua New Guinea.

Aviat Networks installed an entirely off-the-grid microwave repeater and spur atop 11,000-foot Mt. Otto in Papua New Guinea. Image credit: Shutterstock

In all its years, Aviat Networks has installed a great many microwave radios and in some very interesting places. On the sides of the largest dams. On top of the most famous bridges. Deep in the Aboriginal Outback. Way out to sea. In the frozen wastes of the Great White North.

Our latest triumph of man and mechanism over elements comes by way of Papua New Guinea, one of the last lands to be touched by the progress of high technology.

Deep in the heart of this primordial island nation, an imposing mountain stands: Mt. Otto, nearly 11,000 feet (3500m) of steep slopes and very little summit. Few people climb it. There are virtually no roads of which to speak. The only practical way to bring wireless telecom gear up is via helicopter.

However, Aviat Networks was equal to the challenge. Aviat’s services department is loaded with can-do problem-solvers keen to tackle projects like this. In this case, a critical issue for the Mt. Otto site revolved around power. Issue resolved with a big Eltek generator, part of an amazing energy solution that powers an Aviat WTM 6000 14+2 repeater with a 7+1 spur—all built to run at Mt. Otto’s high altitude without supervision for extended periods. If we look a bit closer at the site specs, we will see:

  • 2 x WTM 6000 15+0 Ethernet with 1+1 SDH (design capacity of 3Gbps; normal operation close to 4Gbps)
  • 1 x WTM 6000 6+0 Ethernet with 1+1 SDH (design capacity of 1.5Gbps normal operation; close to 2Gbps)
  • 12 foot antennas in a Space Diversity configuration across a 91km path
  • 8- and 10-foot antennas to other spur sites

Heady stuff.

To keep the site online, an array of 96 solar panels powers the microwave radios with 24 kW of electricity. As backup, the 80KVA Eltek generator provides up of five days of continuous current in case of extended cloudy weather. It is capable of this as it runs on fuel that’s kept warm in a modular container. Otherwise the fuel would freeze solid in the thin mountain air. A large battery installation provides an extra five days of backup power. Those same solar panels top off the charge on these 57,000 pounds (25,704 kg) of batteries. It’s a closed system completely designed for 100 percent off-the-grid operation.

To complete the site, required dozens of sorties airlifting personnel and all the material necessary to build and install the site. Overall, the Mt. Otto site is an amazing accomplishment in a super remote and hard-to-get-to place.

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We Put the Spotlight on Voice Over LTE (VoLTE)

As one of the most anticipated network technologies, Voice over LTE (VoLTE) has been discussed by operators for years. The expectation was that deployments would start in 2013, but roll-outs in North America were delayed.

VoLTE Logo

Logo courtesy of YTD2525 Blog

Operators have faced a series of issues that include poor voice quality and long call establishment times. Once these problems are solved, it is expected that VoLTE will allow operators to provide  voice and data services using an integrated packet network. As the problems described show, the implementation of VoLTE presents challenges for the entire LTE ecosystem including microwave backhaul.

We have produced a white paper to describe some of the VoLTE requirements that must be met in order to overcome these technical challenges, which must encompass a flexible microwave backhaul as a key factor for a successful transition to all-packet voice and video VoLTE  networks. A brief introduction to VoLTE is presented and then different VoLTE backhaul requirements are described with possible solutions.

Click here to download a white paper on this subject titled “VoLTE and the IP/MPLS Cell Site Evolution”.

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Up to the Challenge? Mobile Operators Look for New Business

Up to the Challenge? Mobile Operators Look for New Business

The mobile phone industry has been mature for some time. Around the world, most people who want and are able to use a cellular handset already have one—sometimes more than one. Even with innovations such as HSPA+, LTE and LTE-A becoming mainstream, average revenue per user (ARPU) continues to decline. Mobile operators may be at the crossroads. They are certainly at an inflection point. How to counter the trend is what operators must decide.

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Could the Fixed Microwave Community Live without the L6GHz Band?

L6GHz-spectrum-could-be-allocated-away-from-fixed-microwave-service-at-the-2015-World-Radio-Conference-says-Aviat-Networks-February-14-2014

Photo credit: Broo_am (Andy B) / Foter / CC BY-ND

The fate of the L6GHz band for fixed microwave services could be decided when the World Radio Conference (WRC) meets in Geneva in 2015. Because these meetings at ITU headquarters only occur every three or four years, 2015 will be pivotal. Procedurally, at these conferences, delegates from member states review and—if necessary—revise the Radio Regulations, the international treaty governing the use of radio-frequency spectrum and geostationary- and non-geostationary-satellite orbits. They make revisions based on an agenda determined by the ITU Council, which takes into account recommendations made by previous world radiocommunication conferences.

Generally, the scope of world radiocommunication conference agendas is established four to six years in advance, with the final agenda set two years before the conference by the ITU Council, with concurrence of a majority of member states.

As WRC-15 approaches, many national regulatory authorities are busy harmonizing their national positions this year ahead of the actual conference in 2015. This conference is likely to see one of the biggest—if not the biggest—reallocations of spectrum ever undertaken. Much of this is currently being addressed under agenda item 1.1:

To consider additional spectrum allocations to the mobile service on a primary basis and identification of additional frequency bands for International Mobile Telecommunications (IMT) and related regulatory provisions, to facilitate the development of terrestrial mobile broadband applications, in accordance with Resolution 233 (WRC-12)

This will present the microwave community with a number of challenges and opportunities moving forward, one of which will be how we will address increased demand for capacity arising from mobile operators gaining huge swaths of additional access spectrum, enabling them to offer more and more high-demand, high-bandwidth services. This will require the regulatory environment governing fixed microwave to evolve at least in step or ideally ahead of this demand to ensure microwave remains an attractive and viable means for backhauling this access demand. The second challenge that the microwave community will face with WRC-15 agenda item 1.1 is more urgent: the proposal from Russia to open up the L6GHz band to mobile access.

The L6GHz fixed microwave band between 5925MHz and 6425MHz is available worldwide and with its propagation characteristics provides spectrum that is used for critical long-haul infrastructure links. The very nature of these links means that they are likely to be operational for many years and thus explains why many national regulators report stable and/or low growth in the number of licences issued in this band. In fact, with only a small number of channels available, in some locations congestion is becoming a problem. One scenario where use of this band cannot be replaced is when links have to cross open water, such as the Great Lakes in North America or the English Channel, the Oresund and the Aegean Sea in Europe. Here we see greatly increased activity from those building trans-national low latency networks linking together the various financial centers.

Now that we know the band’s use, why highlight it today?
Admittedly, while the Russian proposal under agenda item 1.1 is for shared access between microwave and mobile access, many industry insiders realize that the two services cannot realistically live side by side in the same geography. It’s not possible because mobile access requires nearly blanket area coverage to be viable. Add the fact that user terminals can be anywhere means sharing is difficult if not impossible to achieve. Some have proposed that mobile access at this frequency will only be attractive in urban areas, leaving rural areas to microwave. This is fine until you need to cross or terminate your L6GHz microwave link in an urban area. In reality, this approach is more of a migration solution than a sharing solution and is not in the best interests of the microwave community.

What to do?
The way WRC-15 works is that each member state has the same weighted vote as every other member. Consequently, any proposal for spectrum reallocation needs to be taken seriously. If there are concerns about a proposal then only by convincing a majority of national regulatory authorities of the validity of your argument can your position prevail. Aviat Networks has been working on several fronts in recent months to achieve a sufficiently large counter vote to the Russian proposals so that the status quo is maintained.

Lobbying national regulatory authorities
Specifically, Aviat Networks and other members of the U.S. microwave community have been working to formulate an American position. At present, this looks promising in terms of our L6GHz stance. Aviat Networks is also active in many African countries helping formulate national positions to oppose the Russians. The position of the African countries is key in this debate because there is not the fallback of long distance fiber. With the distances involved copper has never been a viable option for high capacity services. The current cloud over all this is Europe. Even with Europe’s very strong bent toward supporting growth of cellular services, many countries are still undecided, a situation further complicated by Russia’s CEPT membership. For example, Ofcom (U.K.) despite industry efforts is still unwilling to commit to a definitive strategy—or view—although the regulator admits a position must be agreed upon prior to the conference.

The message above is simple: if you use or want to use the L6GHz band for fixed microwave services find out what your national regulator’s position will be under WRC-15 agenda item 1.1. Remember, there are many bands up for discussion under this agenda item so ensure that you get your answer for the 5925-6425MHz band. Moreover, check whether it is a definitive position then lobby for the status quo to remain and oppose the Russian proposal.

Ian Marshall
Regulatory Manager
Aviat Networks

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VPN Services for Mobile Networks and Beyond

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Photo credit: rfc1036 / Foter.com / CC BY-SA

VPNs are crucial for next-generation mobile networks as they enable 3G and 4G wireless to share a common IP infrastructure as well as support new services, according to Said Jilani, network solutions architect for Aviat Networks. And because Virtual Private Networks (VPNs) can serve multiple sites, multiple applications and multiple customers simultaneously, Jilani believes that they will form the cornerstone for the great expansion of mobile services we are only now beginning to realize.

Serving as one of Aviat Networks’ resident IP experts, Jilani functions as an internal consultant for wireless network deployment and is able to leverage the experience working with different customers in different telecom verticals. And he has seen the impact that VPNs can have in all these markets—not just among mobile operators.

Multi Protocol Label Switching
The great revolution in VPN services for mobile networks is powered by Multi Protocol Label Switching, commonly referred to as MPLS, which offers mechanisms to provide scalable VPN networks, Jilani says. MPLS VPNs come in two main types: L3 and L2 “flavors,” as Jilani terms it.

L3 or IP VPNs, based on Internet Protocol, support very important functionality such as connecting customer sites by emulating a “backbone.” The service provider VPN connects sites in part by exchanging information with customer routers. Offering a robust solution, L3 VPNs easily handle traffic handoff from site to site such as is involved with LTE (Long Term Evolution).

More on L2 VPNs
In the video below, Jilani goes on to elaborate regarding L2 VPN emulation of edge routers and point-to-point Ethernet connections and how L2 and L3 VPNs can function together. Watch it for all the detailed information.

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E-band Wireless Comms: UK Announces New Approach

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-aviat-networks-blog-on-ofcom-e-band-policies-18dec13.jpg

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-Aviat-Networks-blog-on-Ofcom-E-band-policies-18Dec13

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-Aviat-Networks-blog-on-Ofcom-E-band-policies-18Dec13

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.

Ian Marshall
Regulatory Manager
Aviat Networks

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The Rise of Tower Sharing in Africa

Cell-Tower-Ghana-Increasingly-mobile-network-operators-all-over-Africa-are-looking-at-sharing-wireless-towers-to-save-on-microwave-radio-and-other-infrastructure-costs-06-Dec-2012-Aviat-blog

Cell tower, Ghana. Photo credit: aripeskoe2 / Foter.com / CC BY-NC-SA

A growing telecommunications trend in South Africa and other emerging markets across the African continent is the move to cell tower sharing. There are many reasons for this, but the need to reduce capital expenditure (capex) on towers and other infrastructure and retarget spending toward network development, customer acquisition and retention and need to accommodate growing mobile data traffic levels have forced the issue.

The trend toward independent ownership of telecommunications infrastructure such as tower sites, with leasing arrangements for multiple operators on each tower, closely mirrors moves in mature telecommunications markets around the globe, including the U.S. and Europe, as well as other big emerging markets such as India and the Middle East.

Tower sharing prevalent
While there is some reluctance by industry incumbents to offload tower infrastructure because they fear losing market share and network coverage, the tower-sharing model is still becoming more prevalent. This is particularly evident in markets where there are new players trying to penetrate the market, as well as in countries where coverage in rural, sparsely populated areas is needed to drive growth. Other important factors, such as the rising cost of power in South Africa, or unreliable power delivery in other parts of the continent have also helped to drive this trend.

Thus, the adoption of this model has gained significant momentum in Africa since 2008, with major mobile operators in Ghana, South Africa, Tanzania and Uganda striking deals to offload existing infrastructure to independent companies. These independent “tower operators” handle the operation and management of these towers, leasing space back on the towers to multiple network operators. This helps to reduce operating costs, improve efficiency and potentially boost an operator’s network coverage significantly and rapidly.

Smaller equipment requirements
To accommodate multiple network operators on a tower and cell site, smaller antennas are preferred, with additional requirements for smaller indoor equipment that draw less power. This configuration helps to decrease power consumption and cooling requirements resulting in more efficient use of diesel generators during times of power failure. However, having smaller antennas affects transmission power, capacity and efficiency. As such, mobile operators are turning to on-site solutions that offer all these benefits, but do not compromise on quality of service, capacity or data transmission speeds.

This also extends to the backhaul network, which often poses the most significant challenge for mobile network operators, especially as mobile networks continue to evolve from 2G and 3G to LTE. For example, as mobile networks continue to evolve, backhaul network architectures will need to change from simple point-to-point to more complex ring-based architectures. Operators that choose to share infrastructure will need on-site equipment that is capable of accommodating these changes, while still offering optimal transmit speeds and reduced operational costs.

Traditionally, most network operators also used optical fiber for their high-capacity fixed line core/trunking networks. However, as tower sharing becomes more prominent fewer operators are willing to spend the capital required to enable fixed-line backhaul from shared sites due to the associated costs. Therefore, more operators are turning to wireless backhaul as a suitable solution to transport data between the cell site and the core transport telephone network.

More capacity needed
As users demand more capacity on the access portion of the network, the core/trunking network also needs to sufficient capacity to be able to transport the aggregated traffic from all these sites. Many operators have turned to high-capacity trunking microwave systems to provide the required high capacity. These high-capacity trunking microwave systems have traditionally been installed indoors, usually in a standalone rack. They were also installed in a way that radio signal strength diminished significantly before reaching the antenna at the top of the tower, ,necessitating a bigger antenna to compensate. These all-indoor configurations also required big shelters and costly air conditioning.

Developing new technologies
In an effort to improve the efficiencies of mobile backhaul to meet modern demands, tower operators and their solution providers are reconfiguring these shared sites, and new technologies are being developed to solve these challenges.

For example, split-mount trunking solutions allow for up to four radio channels on a single microwave antenna, and lower costs associated with deploying and operating ultra-high capacity microwave links for increased capacity. Smaller and lighter antenna solutions can also be lifted and installed higher on towers more easily, which helps to decrease tower space and loading requirements, making these solutions less prone to wind damage. Moving radios from the shelter to the tower, next to the antenna, further reduces deployment and operational costs and simplifies antenna connections (e.g. eliminates inefficient, long waveguides; costly unreliable pressurization/dehydration systems). In these cases, smaller shelters or cabinets can be used, which decrease air-conditioning requirements even further.

However, regardless of how tower operators are able to reduce costs and improve efficiencies, the trend of this form of infrastructure sharing is set to continue, which will help to drive increased competitiveness in mobile markets across Africa. This will have a positive impact on the prices end-users pay for mobile data and voice services, and will help to accelerate the availability of connectivity across the continent.

Siphiwe Nelwamondo
Technical Marketing Manager, South Africa
Aviat Networks

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Microwave Radios Extend Wide Area Network for Healthcare Provider

Aged-care-provider-Life-Care-decided-not-to-wait-7-years-for-Australias-NBN-National-Broadband-Network-to-reach-the-Adelaide-suburbs-it-commissioned-an-Aviat-microwave-radio-WAN-instead-Nov-1-2013

Aged care provider Life Care decided not to wait seven years for Australia’s National Broadband Network to reach the Adelaide suburbs. Instead, it commissioned an Aviat microwave radio high-capacity WAN. Photo credit: Douglas Barber [CC-BY-SA-3.0-2.5-2.0-1.0], via Wikimedia Commons

Microwave radio is many things: It is an enabling technology in support of the mobile phone revolution and all its dependent social networks. It is a dedicated system that provides the skeleton and musculature (i.e. infrastructure) that allows police, firefighters and other first responders to react in a coordinated fashion to both routine and emergency public safety incidents. But it also serves in lower profile but nonetheless very important niche applications around the world. Take for example the experience of a regional healthcare provider in South Australia.

In a recent article in the national newspaper The Australian, the networking story of Life Care, the umbrella organization for a series of five aged care facilities and 12 retirement “villages” in and around Adelaide, Australia, was detailed. With the rollout of the National Broadband Network slowly progressing across Australia and not anticipated to reach the Adelaide suburbs for seven years, Life Care decided it could not wait so long to connect its locations via high-capacity telecoms. It chose to bid out a project for its own private Wide Area Network (WAN). Aviat Networks partner MIMP Connecting Solutions won the contract as the incumbent vendor. The clincher on the deal: the capability of Aviat radios to connect the farthest outlying facility, at some 50 kilometers, in Aldinga with high-bandwidth wireless. Furthermore, MIMP could offer a licensed spectrum solution, free from interference, whereas the competitors could not. And with a breakeven ROI of just two years, an Aviat-powered microwave WAN was a no-brainer—the others were four-years-plus to payback.

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Lessons Learned: Transitioning from TDM to IP

Cell-phone-tower-near-Lozen-Bulgaria-Aviat-Networks-network-solutions-architect-Hadi-Choueiry-recounts-3-TDM-to-IP-lessons-learned-18Oct13

Cell phone tower near Lozen, Bulgaria. Photo credit: Plamen Agov • studiolemontree.com [CC-BY-SA-3.0 or GFDL], via Wikimedia Commons

The transition from the Time Division Multiplexing (TDM) cell phone networks of the 2G and 3G mobile era has been a long time coming. However, the mobile industry seems to be at one of its proverbial inflection points where IP (Internet Protocol) technology is ascendant and TDM has begun the long but inevitable decline into legacy status.

Aviat Networks has been there all along the way, helping operators design and deploy aggregation systems. We’ve seen and learned a lot as some of the leading mobile phone carriers have upgraded their networks. Now as LTE works its way into mainstream status, cell phone networks are transitioning to full-IP, the underlying technology of LTE.

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60GHz Band: a Solution for Small Cell Backhaul?

60GHz-microwave-backhaul-could-be-effective-solution-for-small-cell-if-regulators-in-various-nations-permit-its-use-says-Aviat-Networks-07Oct13

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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Ian Marshall
Regulatory Manager
Aviat Networks

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