Recently TomsHardware had an exclusive interview with John Storch,the vice president of network deployment at Clearwire. He has directed Clearwire’s network rollouts in 50 cities in the U.s. and abroad.
He explained WiMAX technology in simple words,also shared Clearwire’s WiMAX deployment strategy.Now we share the knowledge with you…


On Why Do We Need WiMAX?
I look at it from two perspectives. Why does the world need a cell phone? If you look back at the early stages of cell phone deployments and cell phone technology, there were certainly folks who said they didn’t need it. There were plenty of pay phones, calling cards, and landline phones embedded in the way we did business. If you look at high-speed data from the perspective of a cell phone, I think the world needs it in the sense that it will “de-tether” a person from a location. Today, most people are tethered to a Wi-Fi hotspot or to a traditional DSL- or other cable-type service.

Now, compared to 3G cellular, I think the world needs WiMAX because the radio technologies out there are all bolt-on.Look at the success of the iPhone. But when you look at those devices, they’re struggling because the network that is underneath them is struggling to support all of those apps and their capabilities in the fullest. WiMAX brings a true broadband, multi-megabit experience to the customer, is going to afford them the ability to use those applications.

On 2.5G it’s OK, 3G is better, and 4G is coming up. Why isn’t that good enough?
Exactly. And dial-up service compared to broadband in the earlier days, with the way the applications were built around it, was good enough. You could chat on AOL dial-up. You could have some of the same interactivities. But you didn’t necessarily have the fullness or the richness of what you can have with broadband. What we’re proposing with WiMAX is that we’ll take that true broadband experience, both in speed and latency, to the mobile environment.

I’ll give you an example. I have friends with 3G iPhones. I personally use a freaky Samsung device. But you go to sporting events and things, and you see that the network is struggling with the ability to carry the traffic. You go through airports, and the networks are struggling to deliver the throughput the devices are demanding.

On Everybody’s expecting broadband apps, not phone calls and IMs. Aren’t we facing the same bottleneck, just with bigger numbers?
At some point there is a capacity limitation to everything, but voice networks have limitations not only at the air link but also in the network itself, the way that it’s handling traffic, how traffic piggybacks with the voice traffic, the capabilities and capacities to the site. Clearwire has actually built a 4G network from the ground up. It’s a completely IP network with very large pipes that run between all of our sites, so that traffic bottleneck is eliminated. There is very little data translation that occurs in our network. We don’t have to go from switch environments to packetized environments and back and forth.

On What’s the difference between a WiMAX signal and a cellular signal?
Cellular signals were designed around low bandwidth and low latency for voice calling. We as consumers are accepting of the fact that 8 kilobits, 6.5 kilobits, or whatever is good enough on cell phone. But when you go to your landline phone, you notice the audio difference. With WiMAX, the channel was designed around low latency again, so you could carry on voice conversations or have real-time interactions, but it was also designed for broad bandwidth. More specifically, if you look at the design of a cellular channel, it has equal sharing of both the uplink and the downlink, which is very inefficient for that limited spectrum resource.
Clearwire has gone with a TDD format, which allows the system to adapt to whichever half of the interaction is “speaking” more. If more bandwidth is needed on the uplink, it shifts to allow you to talk more, if you will. It’s asymmetrical in its proportioning and adaptive to the transaction that’s occurring.

On WiMAX deployment process in US cities
The good news is that most of the network areas in the US have been overbuilt several times by other carriers. We refer to things as “aerial assets”—building tops, traditional cell towers, utility poles, things of that nature. We kind of ride the tide of others before us who have broken ground in these cities. We still have some hurdles, but it’s nowhere like it was in the late ‘80s and early ‘90s with the large PCS build. Clearwire predominantly co-locates rather than erects or develops its own towers, steel or otherwise. Also, we have very low power consumption. We’re a greener technology in the sense that we do have a smaller carbon footprint in the amount of electricity that we consume compared to a traditional cell site—about 1/3 of the electricity of a traditional cell site.

On a lot of Clearwire’s dead spots in Portland
If we don’t serve that area well, we’ll try to set the appropriate expectation for you that says, yes, we are in the area, but we’re not “there yet,” so you might want to wait until our deployment is complete. Or if we are in the area, then we’ll say here’s your service level.

It’s a model, it’s not perfect. We fine-tune it as we go along. So in areas like Portland, we’re continuing to build out, not only with what we call the initial footprint but with also the customer feedback footprint. We had several hundred trial users in Portland, predominately Intel employees, before we launched. So based upon their experiences, where they used it, where they went, and things of that nature, we made shifts to the design and added in sites based on learning popular destinations and how people commute. We’re continuing to see those.
Or perhaps it would work better if customer had a residential unit [Clearwire’s desktop adapter] for now and then moved to a dongle device later.

On Clearwire residential unit doesn’t pull in any better signal than USB dongle.
They’re not too dissimilar. But what we find is there’s often a side of the house that might be better served. So we’ll provide a residential device and one of our Clear [powerline] plugs that allows remoting of the Ethernet. For some folks, that works well. But certainly we keep track of that so we can look to further improve the area. If we’re expecting a better signal, we may actually climb the tower if we’re not getting the expected performance as it sits. We want to understand that because we’re learning about the technology and want to make sure it delivers to its fullest potential.

On What factors influence where Clearwire target for next WiMAX rollouts?
Well, I think one of the biggest factors is our investor group. Comcast, Time Warner, Google, and Intel certainly are big influencers in where we head by the investment that they’ve made in the company as well as their positions on the board. Then there’s customer demand—where the customers are telling us that they’re going, where they’d like to go. From Baltimore, it’s pretty obvious they’re going to D.C., but it’s also interesting how some of the feedback we’re receiving says they’re going to Boston or Philly or even Atlanta.

On Clearwire states a 6 Mbps download rate, but customer could clocked it up over 9 Mbps.
We’re setting the expectation that the service level we’re going to deliver is that 6 Mbps experience you signed up for. But we’re not going to cap you there. If the network can carry some greater capacities within limitations, we’re going to let you have that burstable moment because there’s no reason to hold it back from you. Now, going back to the user trials we did in the early days, we intentionally concentrated users at one factory on WiMAX so we could really load down sectors with random traffic. You can simulate all the traffic you want, but until you get in real user hands, you don’t get what true demand is going to look like. But through those loading experiences with live end users doing whatever they wanted, we were able to design our sites with the needed capacity throughput.

On Clearwire technology evolution
Early cell phones had 10 keys and a send and an end button, really no display or anything. That’s where we are in our technology evolution. We’re displacing the Wi-Fi hotspot, the DSL connection, and things of that nature. I think some of the first levels of evolution are around location-based services. Where things tend to be ramping up a bit more is the whole mobility environment, whether it be the social stuff like Twitter or MeetMe or whatever. You’re going to see adaptations to that go to the smaller device but with a richer experience—a PDA that truly has a broadband connection and allows for real-time imaging experiences or things of that nature.

On Is WiMAX going to function as a VoIP vehicle?
We certainly hope so. It’s already a VoIP platform today. How should I say this? We hope and expect that this will be your enriched telecommunications platform in the same way that your cell phone has become almost your primary telephone. Keep in mind that we’re not there yet when it comes to mobile VoIP. That’s part of the strategy, but we don’t have a timeline for putting that out there.

On Time lags on WiMAX voice communications versus cellular
The Internet is indiscriminate about traffic, whether it be a voice packet, an image, or streaming video or something of that nature. Specific to the airlink, devices communicate that this is a VoIP packet. We manage that in an asynchronous pattern, so that way it doesn’t develop some of the latency and jitters you might have seen from VoIP services such as Skype or Vonage that have to ride and contend with the rest of the network traffic. We handle VoIP packets separately from regular Internet traffic. That allows it to have its own higher level of quality service—a little bit less about bandwidth and more about latency management, which is kind of a new aspect.

Via TomsHardware

Related Posts:

• Clearwire and Cisco Join to Enhance and Expand CLEAR WiMAX Services Throughout the U.S. (2)
• Clearwire Officialy Go Live in Portland : More Videos and Photos (1)
• Clearwire Officialy Go Live in Portland (2)
• Clear Mobile WiMAX in Portland : On-the-Spot Speedtest 2 (0)
• Clear Begin to Provide WiMAX Service in Portland: On-the-Spot Speedtest (1)
• Clearwire Expected Go Live in Portland Early 2009 (0)
• John Saw Talks WiMAX : Welcome to CLEAR Innovation Network (1)
• Clearwire,UQ Communications and Yota Collaborated for the First International WiMAX Roaming (0)
• Huawei was Chosen As WiMAX Radio Access Network (RAN) Vendor for Clearwire (0)
• CLEAR Official Launch WiMAX in Las Vegas : Confirmed for Mac OS X Driver and Samsung Mondi (0)