[opendtv] Re: News: TV Braces for the Apple Tablet

  • From: "Manfredi, Albert E" <albert.e.manfredi@xxxxxxxxxx>
  • To: "opendtv@xxxxxxxxxxxxx" <opendtv@xxxxxxxxxxxxx>
  • Date: Sun, 31 Jan 2010 16:57:52 -0600

Kon Wilms wrote:

>> So as you can see, the spectrum required in the wireless parts
>> of the cell network is not used any more efficiently here than
>> it would be unicasting that video. The advantage of IP
>> multicast is only in the backhaul network. On the other hand,
>> if the cell phone uses a broadcast-only chunk of spectrum, one
>> which does not eat into cell tower's two-way link capacity,
>> that's when you'll see the advantage.
> That is becoming factually incorrect. The latest versions of
> Flash player (yes, Flash player) have the ability to use peer
> to peer broadcasting and *cough* IP Multicast.

Can you explain what "peer to peer broadcasting" means? Does it mean that the 
cell phones create an adhoc network among themselves, each one forwarding the 
multicast packets on to another cell phone within range that is also indicating 
interest in joining that multicast group, without involving a cell tower? (I 
find that hard to believe for cell phones, although MANET does try to implement 
just such scenarios.)

I'm afraid that when you say something is incorrect, without explaining what 
part of what I said is incorrect, the Craigs of this world charge off assuming 
all is incorrect, and they can make up their own version of what is reality.

> The same versions are identical in features on all platforms
> including set top boxes and mobile. Cell phones are becoming
> increasingly multi-homed. Heck with my Nokia N900, the same
> dial pad makes a cellular or skype call, depending on if I am
> connected to wifi or not. I don't think I need say any more
> than that.

Yes, the ability to switch from 3G to WiFi, when WiFi is available, has been 
around for some time. I don't see how this changes anything, though. In WiFi 
hot spots, WiFi can offload traffic from the 3G cell. 3G picocells have exactly 
this same effect. Used mostly for indoor coverage, the picocell also offloads 
traffic from the outdoor macrocell. All you are pointing out here, in effect, 
is that if the cell companies REDUCE THE SIZE of their cells, they can achieve 
greater spectrum reuse. Of course, I agree with that.

> You also forget about HTTP being the new delivery mechanism
> for live broadcasts from CDNs, where any HTTP cache can cache
> content at any edge location.

Again, I don't see the relevance. The big issue here is lack of RF spectrum for 
cellular network traffic, not so much lack of bandwidth in the backhaul 
network. Although that too is an issue, it is not the issue the FCC has to 
solve. If you have the TV programming stored at the edges of the backhaul 
network, transmitting that programming to individual cell phones, over the 
normal unicast cellular links, is what causes the RF capacity problem.

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