Response to Rex ( and All )
<Rex Takasugi>
Donna had a question over on the Motley Fool board concerning MCOM's SuperFast Modem, a super fast chip and the 128 kbps access, and was wondering whether they were one and the same. David is probably the one to answer this, since he's an MCOM engineer, but I'll take a crack at it.
Here's my understanding of what's going on. Going downstream to the user, MCOM is planning on using the purchased spectrum in the 2.3 ghz spectrum. Transmissions in the lab go up to 160 kbps, but they plan on advertising 128 kbps. It may be possible to have this 2.3 ghz go right to the user, but in many cases, there might have to be a step down to the 902 - 928 mhz spectrum to get into the home or building.
<David>
Actually, as of now, this will always be the case, the link from the modem to the poletop will be 900MHz, NOT 2.3 or 2.4GHz, one reason being, as you stated, the difficulty in getting good building penetration using 2.3 or 2.3 GHz. So the next logical question would be. if you are not providing a 2.4 GHz link to the user, how do they get the high data rate? Well, there are things that we are working on to provide that high data rate on the 900 MHz link. So then you might ask, OK. why then do you even need to bother with 2.4 GHz? One the biggest reason is BANDWIDTH. In the 900 MHz band we have 28 MHz of spectrum ( 902 - 928 MHz ) in the 2.4 GHz unlicensed band we have 83.5 MHz (2400 - 2483.5) That's a lot more room spectrum to work with!
<Rex Takasugi>
The radios are smart enough to figure out automatically what spectrum to use. Uploads are on the 902 - 928 mhz spectrum. Newer modems will be required to achieve the 128 kbps speed; older modems will be able to achieve faster speeds, like up to 50 to 60 kbps. The new super fast chip you're talking about must be the one they are going to use in this new modem, but I don't know for sure that they are one and the same.
<David>
Actually, I am not sure what she is referring to either.
<Rex Takasugi>
They have not decided on what to charge for upgrades and faster service, but maybe somewhere in the 2X current rates area.
<David>
Well, See! You guys know more than I do! I have not heard anything regarding pricing!
<Rex Takasugi>
128 kbps will be mostly in place in the SF area by mid to late 1998, but rollout to other areas is scheduled for 1Q 1999.
<David>
I think this is what we are aiming for.
I'm no electrical engineer, for sure, so I hope David will step in here to set me straight if I'm in error in the explanation.
<David>
Good Job Rex! |
