When Comcast officials stood up last week at a Goldman Sachs conference and said that it would soon have cable TV on a mobile phone everyone seemed surprised. Not us. What IS the point of partnering with Clearwire if this is not possible.
Last year we established what kind of video was available on the Xohm (now Clear) WiMAX services, which Comcast will eventually have access to. The service is a 3 Mbps to 6 Mbps broadband line in the home, and if it uses its own femtocells in the home, backhauled by cable, it could reach twice that speed eventually.
The roll out has been very slow and some would argue that broadband sold on its own, with a tentative voice service, is way too little to get consumers to dump their mobile phone. Progress IS slow, but when a full WiMAX network is built out in any given area, it will remain significantly ahead of any non-LTE wireless network, and probably ahead of LTE as well for some considerable time.
The idea is that the TV Everywhere service ‘ the service whereby cable operators let you watch their content free over the internet if you already subscribe to cable – is simply continued onto the mobile internet because of the amount of bandwidth which a WiMAX network can continue to offer, whether it is fixed, portable or eventually fully mobile.
The big difference is in the headline broadband speeds that wireless operators quote. For instance AT&T will quote 7.2 Mbps as a headline speed, versus the Clear WiMAX service which might offer 3 Mbps. It looks immediately like cellular is faster.
The difference is of course incredible in that the WiMAX network is promising that amount of bandwidth to each customer, and though it is not expected to be able to do this around the clock if the network has a heavy video usage, it remains about 8 to 16 times as fast as a cellular network when like is compared with like.
Commercial HSDPA data services are over and above existing voice channels all share a single channel of either 3.6 Mbps or 7.2 Mbps across all the users attached to any given radio in a base station, and it’s for their data requirements only.
In the Clear WiMAX base stations there are about 6 radios, each with over 40 Mbps of usable bandwidth, giving a total throughput of something close to 300 mbps. There are usually 3 radios in a cellular Macro base station, each offering say 7.2 Mbps ‘ 21 Mbps in total.
Simple cellular streaming has been used in WiMAX trials around Sprint and Clear, offering video at a speed of 750 kbps, which looks fine even on a laptop, and on a Nokia tablet it is supposed to look fantastic.
This class of video is at least three times faster than the fastest video offered over a cellular service, where it uses the same channel as the voice traffic. Even DVB-H, ATSC M/H and MediaFLO, which are multiplexed down to something way below 300 kbps, only start out life as a 400 kbps to 500 kbps encoded stream. So in one stroke the WiMAX network is getting ready to shock and awe across the video community. Except for one thing, no one is ready to offer video over WiMAX ‘ yet.
This is Apple iTunes class video, which when delivered as a file resolves to about a 800 kbps stream on a PC or other device, but without the problems of waiting for a download. In short this is Wi-Fi class video performance over cellular distances.
On a handset this is going to look incredible, and every single customer can watch a different channel and the network should have enough bandwidth for around 33% of customers to be watching cable TV at any moment in time.
It won’t be 100% of people because that 300 Mbps will support probably 1,000 customers and the network is being built to have a contention ratio of probably around 10:1. What that means is that everyone expects their 3 mbps or 6 mbps when they are online, but are not online all AT THE SAME time. But when you watch TV over it, many people will be on at the same time.
Broadband users normally tend to ask for non-real time services like requesting html pages, sending email, even uploading home made videos, but on average, although they experience relatively fast broadband speed, they tend never to use more than 300kbps ON AVERAGE over the whole day, because they don’t use it all day. Watching TV, at a constant 750 kbps would mean that if everyone did it, it would break the network. But certainly about a third of them could on a well built WiMAX network and it would hold up fine. By comparison if cellular streaming video is used it maxes out at about 12 people on a base station ‘ a far lower number.
Our guess is that the only thing holding all of this up is that TV Anywhere is not that well used right now, and only in its roll out stages, and that the Clear network is not quite ready for this level of traffic. One of the beauties of a WiMAX network is that you can add capacity as you go, as more customers come online, by in-filling gaps between base stations, so right now it is more important to build coverage than ensure high throughput edge to edge.
When Comcast and the other cable partners in Clear, are comfortable with the condition of the network, the roll out of video services will appear like magic ‘ and if the right devices are in place (think about something like the Nokia N900 or a Netbook) the video would be at least iPhone download quality and potentially beyond.
What surprises us is that it is taking so long. But now that Comcast is just starting to bring it to the attention of investors, the day when cable goes wireless cannot be too far into the future.