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Technology Stocks : LAST MILE TECHNOLOGIES - Let's Discuss Them Here -- Ignore unavailable to you. Want to Upgrade?

To: lml who wrote (2885)	2/16/1999 6:39:00 PM
From: Bernard Levy	Read Replies (2) \| Respond to of 12823

Hi lml: I am not 100% certain, but judging from the operating frequencies of the Global Pacific antennas, and from the footprint of their cells, they are probably using the MMDS spectrum. They advertise their services as ''broadband'' wireless (150kb/sec to 3Mb/sec), but from what I know of the MMDS spectrum (100Mhz bandwidth), if we assume a reuse factor of at least 4 and a spectral efficiency of 4 bits/Hz, the total cell capacity is about 400 Mb/sec. This sounds like a lot, but if you look at the cell maps on their web site, the cells are really big, i.e., there are lots of potential customers per cell. So, if they are really successful, I can foresee a lot of congestion, similar to what you might see on an HFC network with a high user load (wireless likes cable uses shared bandwidth). Note also how big and ugly their antennas are. The frequencies with the true potential for broadband wireless lie much higher in the spectrum, at 24, 28, 38 GHz and beyond for terrestrial wireless, and in the Ka band for satellites. For example, LMDS operators at 28Ghz have 1.3GHz (A and B blocks) to play with (more than 10 times the BW of MMDS, which has itself about 4 times the BW of PCS blocks). The higher frequencies allow also the use of smaller antennas, smaller cells (less users per cell), finer sectorization (say 6 to 8 sectors per cell), and a frequency reuse factor of 1. Of course, the drawback is that line of sight is required, but to accommodate non-line-of-sight conditions for MMDs you need smart antennas (the type of technology that Cisco obtained with the Clarity Wireless acquisition). Best regards, Bernard Levy