September 7, 2012
There’s a lot of buzz in the microwave industry about the trend toward all-outdoor radios, but those who haven’t been through LTE deployments may be surprised to learn that based on our experience deploying LTE backhaul for some of the world’s largest LTE networks, all-indoor is actually the best radio architecture for LTE backhaul.
We can debate today’s LTE backhaul capacity requirements, but one thing we do know is that with new advances in LTE technology, the capacity needed is going to grow. This means that microwave radios installed for backhaul will likely have to be upgraded with more capacity over time. Although people are experimenting with compression techniques and very high QAM modulations and other capacity extension solutions, the most proven way to expand capacity is to add radio channels because it represents real usable bandwidth independent of packet sizes, traffic mix and the RF propagation environment.
All-indoor radios are more expensive initially in terms of capital expenditures, but they’re cheaper to expand and (as electronics are accessible without tower climb) are more easily serviced. While an outdoor radio connects to the antenna with Ethernet or coax cable, indoor radios usually need a more expensive waveguide to carry the RF signal from the radio to the antenna. So you pay more up front with an all-indoor radio but as the radio’s capacity grows you save money. There are several reasons.
When everything related to the radio is indoors, you just have a waveguide and an antenna up on the tower. To add radio channels with an all-indoor radio you go into the cabinet and add an RF unit. With an outdoor radio, you have to climb the tower, which can cost as much as $10,000. Also, when you add a new outdoor RF unit you may have to swap out the antenna for a larger one due to extra losses incurred by having to combine radio channels on tower….(read the full story at RCR Wireless).
Senior Product Marketing Manager
July 10, 2012
Migrating legacy mobile backhaul networks that were designed for TDM traffic to add support for high-speed Ethernet data for 3G and 4G mobile technologies is one of the biggest challenges for operators worldwide. Each case is unique and poses its own quirks and potential pitfalls. Mobile operators must juggle new technologies, cost pressures and the need to maintain existing services or risk driving customers to the competition.
For Safaricom, the leading mobile operator in Kenya and one of largest in all Africa, the case involved preserving its E1 capacity for voice calls and simultaneously adding Ethernet/IP bandwidth for burgeoning 3G and WiMAX data traffic. As many mobile operators have done in the past, Safaricom built its network over time. Many parts of the network are still legacy 2G TDM technology. However, things are changing rapidly, with 3G subscriber numbers up 85 percent in 2011 year over year.
Many of these subscribers are consuming ever-increasing amounts of data bandwidth. Safaricom’s TDM based backhaul, making use of Ethernet-to-E1 converters, is finding it hard to keep up with demand. To help resolve the situation, the operator called on Aviat Networks, one of its incumbent solution providers. Using its market leading hybrid radio solution, the modular Eclipse microwave networking platform, Aviat Networks enabled Safaricom to add IP data capacity as necessary while keeping E1 capacity for voice calls.
In addition, the stage has been set for Safaricom to make the eventual migration to all-IP backhaul. With the modular Eclipse platform, it can transition on its own schedule. For more information, read the complete Safaricom case study in the frame below or download the PDF:
November 20, 2011
What is the best migration strategy for utility networks migrating to Smart Grid using Hybrid Radios? We look at the technology choices that are available to support legacy TDM and IP-based services and investigate the many demands placed on utility networks. Demands include seamless migration, increased capacity, security, and interoperability.
We believe a hybrid network is the best solution and we explain why in this white paper:
September 22, 2011
Our partner, Symmetricom, recently announced the launching of a new segment of their SyncWorld ecosystem for microwave backhaul. Our hat’s off to them; this is great news for Symmetricom and the new players that are now on board. We boarded this train awhile back. After a couple years of collaborative testing between us, we first joined the ecosystem when it was initially launched in March at CTIA 2011.
So, what have we learned since then you might ask?
Well for one, packet based timing is still growing in interest, evaluation, and deployment. Customers around the world — including mobile operators, state and utility providers and others – are increasingly looking for timing solutions that operate over their Ethernet fiber and microwave network as effectively as their TDM timing solutions do. A recent Heavy Reading analyst report projects close to 2 million cell sites will have deployed the two most dominant solutions, IEEE 1588v2 and Synchronous Ethernet (SyncE), by 2015.
Secondly, we’ve learned this is by no means the technology race it started out to be. Remember when Blu-ray and HD–DVD were competing a few years ago? Or perhaps that has well faded into memory. Well, I still recall the industry buzz a couple years ago about whether Synchronous Ethernet (SyncE) was going to kill IEEE 1588v2, or vice-versa. Who was going to come out on top?
Telecom watchers and players are always primed for a tech battle it seems. Well lo and behold; this battle has become more of an alliance, as of late.
The dominant discussion today is now about how BOTH these technologies can co-exist, and where best to deploy them in a network, either side by side or in parallel, with one backing up the other. Hmmm, now that’s an interesting conclusion to a tech battle.
Case in point, a couple of our customers are planning to deploy both technologies to take advantage of their respective strengths and are in the process of doing just this. See this whitepaper for more information about synchronization over microwave backhaul or maybe this one for insight into deploying IEEE1588v2 synchronization.
So, with the reality today that packet timing is still growing and that options for packet timing (including TDM, 1588v2, SyncE, and GPS) will continue to co-exist for a long time, it becomes even more critical to seek experience when it comes to planning your sync migration.
An ecosystem is probably a good place to start, especially with those players that have been at it for some time.
Sr. Manager, Solutions Marketing
August 5, 2011
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.
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.
July 29, 2011
The cloud is an all-encompassing thing that’s actually been around for a while (e.g. distributed computing, Network Attached Storage). Most of it exists today in the enterprise but is being pushed to the Internet and rebranded “The Cloud.” This affects three wireless networking segments: consumers (e.g., you, me, mom, dad), Internet providers (e.g., mobile operators, ILECs, CLECs) and wireless solutions vendors (e.g., Symmetricom, Aviat Networks).
For consumers, it represents the ability to store information—pictures, music, movies—virtually and access them wherever we go from devices of our choice. No longer do we have to worry about backing up smartphones, tablets or laptops. The downside is that this magic is going on in the background all while your data caps are being reached. So, watch out….
On the mobile operator side, this will represent a substantial increase in bandwidth used. In addition, bandwidth usage starts to become more symmetrical as more uplink bandwidth is utilized while uploading to the cloud. This also means more frequency consumption on the RAN-side as subscribers stay “on” more often. Operators need to figure how to get users off the air interface as quickly as possible. This calls for greater throughput and potentially much lower latency. Trickling data to end users compounds the air interface problem. For the most part, subscribers won’t realize what’s happening and data caps are more likely to be reached. This translates into either more revenue and/or dissatisfied customers. Clearly, operators must monetize transport more effectively and at the same time provide more bandwidth.
Lastly, for wireless solutions vendors this translates into increased sales of wireless equipment to ease the sharp increase in bandwidth consumption. This also translates into more intelligent and robust network designs (e.g., physical and logical meshes, fine-grained QoS controls) as subscribers rely more on network access for day-to-day activities. As for the cloud in general and the overall effect:
Therefore, the amount of bandwidth consumption will rise dramatically this September when Apple releases iOS 5 and iCloud. Android has already driven much bandwidth demand, but it’s not nearly as “sexy” as what Apple is releasing for its 220 million users—or alternately total iOS devices: iPod touch, iPad, iPhone). It’s more than just bandwidth—it’s quality, reliable bandwidth where QoS and Adaptive Modulation will play significant roles—of this, I’m certain.
At a recent TNMO event they were talking about LTE-Advanced and leveraging the cloud for virtual hard drives. Imagine, no physical hard drive in your computer. Laptops are connected via 4G wireless/5G LTE wireless to a cloud-based hard drive, equating to lots and lots of bandwidth plus stringent latency requirements….
Director of Product and Solutions Marketing, Aviat Networks
July 20, 2011
There is no one-size-fits-all wireless network backhaul solution. What will work for some operators’ mobile backhaul will not work for others. Many operators have large installed bases of TDM infrastructure, and it is too cost-prohibitive to uninstall them wholesale and jump directly to a full IP mobile backhaul. There is going to be a transition period.
The transition period will need a different breed of wireless solutions. Fourth Generation Hybrid or Dual Ethernet/TDM microwave radio systems provide comprehensive transmission of both native TDM and native Ethernet/IP traffic for the smooth evolution of transmission networks. They will enable the introduction of next-generation IP-based services during this transition period.
We will explore this category of digital microwave technology for wireless backhaul, which is becoming ever more important as the 4G LTE wireless revolution gets underway with all due earnestness, even while the current 3G—and even 2G—networks continue to carry traffic for the foreseeable future.
Our current white paper builds on Aviat Networks‘ previous April 2010 white paper titled “What is Packet Microwave?” and provides market data from recent industry analyst reports that demonstrate the significant and continuing role of TDM in mobile backhaul networks and some of the prevailing concerns of operators in introducing Ethernet/IP backhaul services.
If you’d like to talk to someone about the ideal wireless network backhaul solution for you, please click here.
June 10, 2011
TDD, or Time Division Duplex, where a single radio channel is used to send and receive data, has been a common technique employed in unlicensed microwave transmission bands, such as 2.4 and 5.8GHz. The advantage of TDD is a simplified and lower cost design, often based upon 802.11 standards. In contrast, FDD, or Frequency Division Duplex, where data is transmitted in one frequency channel and received in another (separated by anywhere from less than 100 to more than 1,000 MHz) has been the staple of licensed frequency bands between 2 and 38 GHz worldwide.
Now, a number of the CEPT recommendations for the new point to point bands over 40GHz contain provisions for TDD operation. TDD is accommodated either as an alternative band plan or a mixed TDD/FDD band plan, in addition to the more common FDD band plan. However, CEPT recommendations are only just that—recommendations. How these bands will be implemented in each country will be determined by the individual national regulatory authority.
Recently, we asked a number of European national regulators about if and how they would introduce TDD operation in these new bands. The general response was that they were not opposed to the introduction of TDD in principle, and that such operation would have to be worked into existing or revised band plans. One complication raised was that spectrum would have to be reserved for guard bands between TDD and FDD segments within the same band. Regulators usually try to avoid having to waste valuable spectrum in this way. Also, once a band plan is established and the spectrum allocated to users, efforts to introduce TDD operation at a later date is extremely difficult.
Some regulators have already issued new national band plans at 42GHz and above, and to date none of these allow for TDD operation. Furthermore, for countries that have allocated new bands through spectrum auction, there we see the usual FDD style symmetric band approach.
Despite the appeal of TDD operation from a cost perspective, early indications are that although provision for TDD operation is being made in these higher bands, practical complications and concerns over maximizing the use of new bands may prevent its widespread introduction.
What are your thoughts on using TDD more in national band plans? Leave a comment, if you’d please.
Regulatory Manager, Aviat Networks