- August 7, 2014
- Aviat Networks, backhaul, LTE, microwave, Microwave backhaul, Microwave Radio, Microwave transmission, Mobile network operator, mobile networks, Mobile Technology, technology, 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.
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”.
- September 20, 2013
- Aviat Networks, Back Office, Business, Ian Marshall, Investing, latency, Latency (engineering), Low latency, microwave, technology
Over the course of the last 18 months, a new application has grown by leaps and bounds for microwave networks: low latency. Low-latency microwave networks find most of their applicability in financial transactions, such as for executing trading instructions between major stock exchanges and trading houses in other cities.
Typically, low-latency microwave is used to “replace” traditional-fiber based networks linking financial centers. The business driver for microwave-instead-of-fiber in low latency is the time it takes to transmit trading instructions. With microwave, latency is reduced by a few milliseconds as compared to fiber. Nevertheless, those few milliseconds can translate into a trading edge over rival investors, which means big bucks. Low latency investors will pay a premium for this edge resulting in increased revenue for low-latency microwave network operators.
However, as with most financial functions, low latency is subject to a set of stringent regulations. The scenario is doubly difficult when low-latency microwave networks transmit across international boundaries. This compares to linking financial centers within a single country, which is relatively straightforward from a regulatory perspective because there is only one set of rules. The fact is when connecting financial centers in different nations and the operator’s network has to traverse other countries’ borders, the process becomes orders of magnitude more complex. Download the complete article for a fuller examination of some of these issues and why there should be widespread support for greater international harmonization of microwave regulation.
Ryan Bruton: Aviat Networks senior international marketing manager.
As the summer in the Northern Hemisphere quickly draws to a close, we can look back to the beginning of the season to see what was on the mind of the backhaul market. Our international marketing manager, Ryan Bruton, gave an interview to CommsMEA covering the trends in backhaul for this time period.
In microwave backhaul, for the African market, radio links are averaging around 40 kilometers in length, says Bruton. This is due in part to climatological conditions, but other factors could also be involved, he says. However, in the Middle East, the typical microwave backhaul links are above this average—also partially due to the atmosphere and geography.
Another big trend Bruton sees this summer in backhaul includes the barriers to fiber being used in the Middle East and Africa markets. Accordingly, fiber is very difficult to trench over kilometers and kilometers of open desert. The terrain is inhospitable and very tough on fiber due to high heat and arid conditions. Not to mention bringing in the equipment necessary to install long fiber routes can be a very large obstacle if the paths lay some distance away from existing roads and other infrastructure. Going through the lush flora of Africa, such as in Nigeria, trenching fiber presents a different yet also nearly insurmountable set of barriers, with massive stands of sometimes-centuries-old trees. And clearcutting tropical rainforest to make way for a fiber backhaul route is neither cheap nor “green.”
Microwave is both the more cost-effective and greener alternative compared to fiber-optic technology for wireless backhaul. Currently achieving about 50 percent of the total market share for backhaul worldwide, microwave certainly is a driver for mobile and other wireless network operators.
Then there is always the potential for fiber to fall victim to so-called “backhoe fade,” a euphemism for the accidental cutting of fiber lines by misguided digging operations. But there is always the potential that fiber cuts are not accidental. In any event, fiber is vulnerable to cuts over the entire course of a route—from Point A to Point B. Microwave sites are isolated to a single spot where they may be assailable. At least operators have the option of “hardening” their microwave sites for maximum uptime, whereas, again, this would be too cost prohibitive in the case of fiber over an entire route.
- August 9, 2013
- Africa, backhaul, Cape Town, device availability, LTE, microwave, network investments, Nigerian Communications Commission, South Africa, technology
Africa’s only dedicated LTE event, LTE Africa 2013, took place in Cape Town this July 2013, bringing operators, vendors, mobile device makers, regulators and standardization bodies together under one roof to discuss LTE. On the agenda were the opportunities LTE can bring, obstacles to deployment, monetization challenges, current African success stories and future directions that LTE may take in Africa.
At the conference, operators grappled with the opportunity they face with LTE. What emerged as the main challenges for operators were spectrum, monetization and device availability—at the right price—for the African market.
In many exchanges, policymakers and regulators were beseeched to make spectrum available for LTE. Dr. Ernest Ndukwe, former CEO of the Nigerian Communications Commission, said, “Unless African leaders create an environment which encourages broadband network investments and makes it easy for companies to roll out broadband services, the situation is unlikely to change in the near future.” Operators were equally concerned about monetization of LTE so as to be able to recover their CAPEX—not to mention OPEX. (Others have not fully recovered their investments on 3G yet!)
Nonetheless, they are now expected to move to LTE. It was clear that operators would need to innovate how they do business by implementing new pricing strategies such as “value bundling” solutions, which would move them away from the cost-per-megabyte pricing tariff they firmly cling to today. Finally, a mobile device priced correctly for the African market has been earmarked as the enabler needed for massive adoption of LTE in Africa.
However, the conference was not all gloom and doom as operators who have successfully implemented LTE, such as Smile, MTC and others, shared information on how they made it possible. They highlighted how they implemented LTE. One of the key areas they focused on was in what way they backhaul LTE traffic.
Successful implementations revealed that for Africa—considering Africa’s demographics—practical and cost-effective implementation of LTE does not allow for 100 percent fiber backhaul, especially since realistic throughput demands of a typical three-sector LTE site max out at about 150 Mbps. With microwave systems easily able to reach 400 Mbps and even 2Gbps, microwave is more than capable of catering to an LTE site’s requirements and is undoubtedly the technology of choice for LTE backhaul except at sites where fiber already exists.
Microwave has cost benefits when deploying in areas lacking fiber, and it can be a cost-effective way to connect rural areas. Microwave also has the benefits of being quicker-to-deployment compared to the trenching needed for fiber. By 2017, industry analysts foresee that microwave backhaul will account for more than 50 percent of all LTE cell sites in Africa.
Technical Marketing Manager, South Africa
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 19, 2013
- English Channel, Federal Communications Commission, Frankfurt, high speed network, London, Low latency, microwave, microwave networks, New York, technology, Wireless network
Germany is well-known for its autobahn highway system, where there are no official speed limits. Now there is a new high-speed network that traverses Western Europe from Frankfurt in Germany to London in the UK.
In addition, you may have read elsewhere in recent weeks about low latency microwave networks being constructed in the United States in support of the financial markets. The busiest route there is between the financial centers in Chicago and New York, where microwave can shave off 5 milliseconds off the transmission time along the 700 mile (1,000 km) route when compared to fastest fiber network (13 milliseconds). This saving directly equates to revenue for trading houses that are able to leverage this speed advantage.
In the United States, planning and deploying a point-to-point (PTP) microwave network is relatively predictable and straightforward: acquire sites and avoid interference from other network operators. Where PTP wireless networks cross state boundaries, a network operator need only deal with the national telecom regulator, the Federal Communications Commission (FCC), when obtaining required licenses to operate the microwave system.
But in Europe, this is a very different matter. While trans-European fiber networks have been a reality for many years, a microwave route like London to Frankfurt must traverse several national borders, forcing operators to deal with multiple regulators, with complex negotiations needed for microwave paths that cross national boundaries. For this reason very few—if any—microwave networks of this type have been built, up until now. However, the opportunities offered by the combination of the new low latency sector, along with the performance advantage of microwave over fiber, have now made the case for these kinds of networks compelling enough to outweigh the challenges, and costs, of planning and implementing them.
For a low-latency microwave network servicing the financial sector on the London-to-Frankfurt route, there are a number of major challenges beyond just identifying and securing suitable sites and coordinating frequencies. The difficulty of planning a long trunk route is also greatly exacerbated by going through the densely urbanized region of Western Europe. This results in a constant iteration between finding the right route, identifying accessible sites, and securing required microwave frequencies. To be successful you need all three—a site on a great route is useless if no microwave spectrum is available. All the while, there are other competing providers all trying to complete the same route in the fastest time possible—not only in latency terms, but also time to revenue.
This poses huge potential pitfalls in having to take the long way around, requiring additional sites and links, if a site is not available. The added latency caused by any such deviation could kill the entire project. This race is like no other in the microwave business—whoever is fastest wins first prize, and it is winner take all in this competition. The potential revenue for the London-to-Frankfurt low-latency path is quite staggering, even on a regular day, but on busy days when the market is volatile the potential can be much higher. Operators can plan on recouping their total investment in the microwave network in well under a year. Then once you have the most direct route, compared to your competitors, your problems may not be over, so it can come down to squeezing those extra few microseconds, or even nanoseconds, out of your equipment.
On this particular route there is also one significant natural barrier to contend with—the English Channel. There are only a few ways across that are short enough to allow a reliable microwave path, space diversity protection is a must and only a few towers are tall enough to support these distances. Even though there are no obstacles over the channel (apart from the occasional container ship), towers need to be high enough to allow the microwave signal to shoot over the bulge of the earth. Again, securing tower space at these sites is critical to success, but also obtaining the right to use one or more of a finite pool of available frequency channels, otherwise fiber may be needed across this stage, adding latency. One group even took the step of purchasing a microwave site in the Low Countries to secure it precisely for this purpose.
London to Frankfurt will only be the start for low latency microwave networks in Europe, as there is always a need and an opportunity to provide competitive transmission services to other financial centers throughout the continent. The winners will be those with the speed and agility to quickly seize these opportunities, along with working with the right microwave partner who can help them with the intensely complex business of planning and deploying these trans-national networks, and who can also supply microwave systems with ultra-low latency performance.
We will have more to say publicly on this topic in the near future. Or if you prefer not to wait that long, we would be more than happy to have a private conversation about low-latency microwave with you.