OT to valueman
MCOM has 26 MHz bandwidth in the 902-928 MHz band, and 84 MHz bandwidth in the 2.4-2.484 GHz band. (They also use licensed spectrum for downstream transmissions from wired access points to 'poletop' microcell receiver/transmitters.) By comparison, cellular providers typically have 25 MHz bandwidth available to them in the 800 MHz band, and PCS provides typically have 30 MHz bandwidth available to them in the 1900 MHz bands.
So in terms of bandwidth, the systems are comparable.
The 2.4 Mbps rates quoted for the QCOM/HDR system are not user-sustained data rates, but burst rates for raw data. This is often misunderstood, and is false advertising. After factoring in the carrier to interference ratios, you may be more likely to only get burst rates of 400-800 kbps. Let's assume 600 kbps for sake of argument. Then, the usual rule of thumb is that the *average* data rate is 1/3 of the burst rate, or only 200 kbps in this case.
Comparable to MCOM, not superior. Current MCOM rollout 'promises' 128 kbps, and the San Diego beta test of the operational system reportedly yielded 170 kbps.
Further, MCOM is going to be upgrading to 384 kbps next year.
So I don't view MCOM as 'toast,' by any means. Realistically, they have a multi-year lead on the HDR and EDGE rollouts that are only being planned at this time.
Now, on to your other point about HDR using 'shoe-box sized stations': are you saying that the HDR system will employ a microcellular architecture akin to MCOM, with higher density of HDR stations within a given cellular footprint? I hadn't heard this one. Are these HDR stations independent repeaters to the main base station, in this case, in the same way that the MCOM architecture operates?
If HDR follows the MCOM model of a mesh of microcell transmitter/repeaters, then they would have a chance to match what MCOM is offering now. At best. Can you confirm that this is their design? The last I looked, the HDR systems being proposed used cellular architecture identical to the fundamental existing cells, and did not employ any subdivision of the footprint.
Additionally, to match MCOM's average throughput per POP (user), such a proposed microcellular HDR system would need to use the full 30 MHz bandwidth of the service provider, thus squeezing out the voice channels. This is unlikely.
In summary, IF QCOM were to follow with a microcellular architecture, and the associated costs of negotiating for rights-of-way, etc., for all the nodes (which MCOM has already done across the country), THEN they could begin to construct a system comparable to what MCOM is already rolling out.
You still need to rethink just who is 'toast' here, and who is a few years ahead.
Sidebar: The comment about frequency reuse does not refer to the presence of multiple users in the same frequency band. It typically refers to the need to allow adjacent cells to utilize the same frequency bands. For current voice systems, which are not as robust to interference, quite often adjacent cells do not use the same frequency bands, but only cells that are one step away are allowed to 'reuse' the frequencies (think about the near-far problem, and needing to communicate from the base station to the user on the edge of the cell, and that it is desireable to minimize interference with the adjacent cell). In the context of the microcellular architecture, I used the phrase to refer to making the microcells smaller by reducing the transmitted power as you increase the density of ('poletop') microcell transmitters within a given region.
PS I had heard that QCOM reported only about 40 kbps from field trials of their interim '1x/144kpbs' design, not the oft-quoted 144 kbps. |
