Today, Public Safety networks need to support a growing range of customers, applications, and services. Along with the increasing amount of mission-critical traffic to support public health and emergency responses, most agencies are also supporting traffic involving other agencies, consolidating inter-, intra-, and adjacent agency traffic over a common infrastructure.
5G and rural broadband networks are on track to quickly outgrow the capabilities of microwave-only backhaul solutions. Taking a different, more flexible approach to backhaul planning and availability targets will be key to keep pace with capacity demands and control costs.
The American Rescue Plan Act (ARPA) of 2021 allocates $350 billion to help states, counties, cities, and tribal governments improve their capabilities, infrastructure, and services to better respond to and manage the pandemic. This represents a unique opportunity not only to improve strained backhaul networks for public safety agencies but also to support the advent of 5G and a raft of new public safety applications.
Is traditional microwave dead? With the advent of Multi-Band, it could be. Why accept an old solution when you can have so much more by combining E-Band and traditional microwave into a single-box unit. Governments are taking action across the world to connect homes and businesses in rural areas to the rest of the world. From the 7-year action plan devised by National Broadband Ireland (NBI) to the Federal Communications Commission’s (FCC) $9.2 billion newly implemented Rural Digital Opportunity Fund, there is a worldwide focus on the connectedness of rural areas. As capacity demands increase rapidly for rural broadband networks, a better solution than traditional microwave is needed.
When it comes to delivering the best in wireless backhaul solutions, Aviat sets the bar high, and now we have been selected as one of the “best-positioned suppliers” for the OpenSoftHaul (OSH) global RFI sponsored by Telecom Infra Project’s Wireless Backhaul Project Group (WBH PG).
Through various innovations, wireless transport technology has consistently surpassed capacity demands through 2G, 3G and 4G transitions and remains on trajectory to continue in a 5G network. Reliability of wireless backhaul products has never been better, and costs continue to decline especially relative to fiber-based options. From a product point of view, many good and reliable options exist that cover all frequency bands and form factors to solve the problem of backhaul, small cell and other sub-applications.
In South Africa, as in many emerging markets, wireless backhaul has long been a proverbial bottleneck to network growth. Due to cost and logistics, fiber optic technology remains out of reach as a practical solution for most aggregation scenarios, save for urban applications where population density and shorter routes can justify the exorbitance.
Now with the advent of higher speed, higher throughput mobile phones and tablet PCs, higher-order networking technologies are being pressed into service. Standard microwave radio, while cost efficient and effective for crossing far-flung forests, monumental mountains and desiccated deserts with traditional payload such as voice calls and moderate data rate applications, was not designed for the connectivity and capacity requirements of Layer 3 services. Thus, the bottleneck has grown still narrower. Even to the point where standard microwave radio might be hitting its upper threshold for serving mobile broadband.
Technical marketing manager, Siphiwe Nelwamondo, recently sat down with Engineering News, to discuss these issues and the present and future of microwave radio backhaul in South Africa and across the continent. In addition, he delved into how microwave networking is bridging the radio-IP gap for Layer 3 services by running IP/MPLS protocols on converged microwave routers.
As more and more mobile services get pushed out to the edge of the access network, the imperative for Layer 3 will only grow. Even as 3.5G and 4G mobile users who depend on full-IP increase in number, a majority of second- and third-generation subscribers will continue to rely on circuit-based technology. Not to worry, Nelwamondo covers how TDM telephony will be supported in a converged microwave and IP environment.
The full article goes on to discuss how mobile operators will strategize providing enterprise services from the cellular base station with microwave networking, virtual routers and more.
Wireless backhaul operators, both mobile phone networks and others carrying dedicated traffic, face the constant issue of maximizing the functionality of their systems.
In the emerging markets around the world, the pressure can be most intense. Wireless network reliability, availability and capacity all need to be increased. Customer expectations are on the rise, and operators must take the appropriate steps to meet and exceed them.
In working with MTN Ghana, Aviat Networks recently completed an implementation to increase network visibility (i.e., intelligence) by close to one-third. Aviat’s professional services experts designed the mobile operator’s backhaul links for high capacity and resiliency. Using ProVision, Aviat’s leading network management software, MTN Ghana can now administer its wireless backhaul efficiently and effectively with a reduced level of manpower.
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.
Because of need for higher capacities, the trend toward shorter link distances for mobile backhaul and declining product costs, 70/80GHz (i.e., E-band) solutions are gathering significant interest for mobile backhaul and enterprise access applications. However, because these frequencies are new to most people, there is little understanding of costs and other issues related to licensing the 70-80GHz spectrum.
Last autumn we wrote about potential plans from a microwave competitor regarding using asymmetric band plans for point to point microwave communication links. To update this topic, we have put 10 things in parentheses that you should know about the current status of asymmetrical links in wireless backhaul. Last month at an Electronic Communications Committee SE19 (Spectrum Engineering) meeting this microwave technology subject was discussed again. (1) The proposal under consideration has been reduced in scope and (2) the regulators present still wish to see more evidence regarding the need for change before agreeing to such significant amendments.
Asymmetric Band Plan Altered
A quick reminder of what was originally requested back in the autumn of 2011; a move from channel sizes of 7, 14, 28 and 56MHz to channel sizes of 7, 14, 21, 28, 35, 42, 49 and 56MHz in order to support different granularities of channel widths in all bands from L6GHz to 42GHz. However in March these proposals were altered to reflect channel sizes of 7, 14, 28 and 56MHz (i.e., no change to existing channel sizes) and asymmetric only in the 18GHz band and above.
The national regulatory authorities stated that even the (3) revised proposal cannot be accommodated with existing planning tools so they cannot imagine asymmetric links being deployed alongside existing links in their countries. A few stated that in block allocated spectrum the owner of the spectrum may be able to implement this channelization, but Aviat Networks believes that (4) the complexity of coordinating links even in block allocated spectrum should not be underestimated.
Traditionally, links are planned on an equal bandwidth basis, e.g., 28MHz + 28MHz, with a constant T/R spacing throughout the band in question. This new proposal would see links of 28MHz + 7MHz and furthermore makes the claim that spectrum would be saved. Numerically speaking this arrangement would save 21MHz for each pair, but (5) saved spectrum is only of value if it is reused. In many cases the “saved” spectrum would be orphaned due to difficulties coordinating it into usable pairs.
Asymmetric Channel Plan Limits Future
In our last blog on this topic we reflected on the fact that while there is some level of asymmetry today, (6) this trend may well be balanced in the near future by cloud services and other services that involve the user uploading content. We believe that (7) committing to an asymmetric channel plan now limits the future. (8) Symmetric channel planning allows networks to dynamically adjust to changing demands. A related concern is the fact that (9) spectrum once reallocated may not be easily clawed back to create symmetric pairs in the future. While some applications are experiencing asymmetry in traffic presently, we should not forget that some traffic patterns are still symmetric and where asymmetry is a feature, (10) the scale of this phenomenon may be overstated. Indeed, a major European operator present at the SE19 meeting voiced skepticism about the need for asymmetric support.
What do you think? Will mobile traffic remain or increasingly become asymmetric? Are asymmetric microwave links needed or can they be practically deployed in existing bands? Answer our poll below and tell us. Select all answers that apply.
Balancing cost and performance is a tough act for most operators dealing with telecom networking, especially when it comes to equipment procurement. Getting all the bells and whistles can sometimes result in having a lot of options to choose from. Often times microwave users have to juggle with a variety of radio options that suit a particular site requirement, for example, having to select between low power or high power radios to meet varying distance or system throughput/gain needs. Depending on location and licensing requirements, this may even translate into different products types for different frequency bands. More products result in more spares to maintain in inventory, along with added support and maintenance, inevitably leading to higher costs.
To help address this challenge, Aviat recently unveiled the industry’s first universal outdoor unit (ODU) to support software- defined base and high power modes in a single ODU, with Aviat’s unique Flexible Power Mode (FPM) capability. FPM allows operators to optimize both cost and performance, minimizing their overall total cost of ownership, by paying for the power they need only when needed. As a result, operators can procure a single ODU for multiple locations and via a simple software licensing mechanism, remotely adjust the transmit output power to meet the needs of a particular site. No need to spare multiple radios, nor deal with the operational burden of managing and supporting a variety of product options.
Additionally, operators can apply this flexibility to migrate from legacy low power, low capacity radios to a high power and performance ODU to support much greater link throughput, without having to change their installed antennas. This minimizes both their CAPEX and OPEX while migrating their network from a legacy low capacity TDM microwave link to a high speed Ethernet one.
So while juggling may still be a well needed skill to survive in Telecom, Aviat is reducing the load when it comes to microwave networking. Click here to find out more.
Senior Solutions Marketing Manager