Wi-LAN Inc. (T.WIN) Message Board

STOCKTALK

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor. We ask that you disable ad blocking while on Silicon Investor in the best interests of our community. If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.

Technology Stocks : Wi-LAN Inc. (T.WIN)

WILN 1.390

0.0%

Sep 18 5:00 PM EST

Public Reply Prvt Reply Mark as Last Read File

Previous 10 Next 10 Previous Next

To: axial who wrote (7083)	5/22/2001 12:20:30 PM
From: Rob S.	Read Replies (2) of 16863

OFDM is being considered by many as the base modulation scheme for 4G - necessary to achieving the deliverable bandwidth needed. Properly, however, multi-modulation is beginning to be viewed as the necessary direction WBB will take. MM uses a mix of modulation schemes that may include OFDM, TDMA, FDMA, and TDD. It also uses smart antenna technology. All the versions of MM that I have been able to find in a patent search use OFDM as the base modulation scheme and then use TDMA and/or FDMA to time slot and frequency map beam patterns which are formed through the use of adaptive array antennas. The objective of these various systems architectures is to target signals to a user or groups of users on a location-demand basis rather than a gross sector reuse basis. Projected spectrum reuse is in the area of an order of magnitude (10x) or greater. The reach of these systems is also expected to be greater as the beam is shaped so that the energy more effectively reaches the target user(s) rather than being dispersed on a more random basis. The earliest examples of MM technologies that are likely to emerge into commercial products are IoSpan and BeamReach. AT&T and Lucent (Bell Labs) spin off Flarion are also active in developing MM technology. The main arguments against the implementation of MM for commercial applications is that it is complex and requires increased processing (DSP) capability that drives up cost. If a smart antenna is used at the CPE end as well as the base station, the cost per user has been thought to be overly expensive. The main factors driving towards acceptable costs of MM is the increasing capability of DSP cores and communications ASICs. Also, the cost of adaptive array antennas has been reduced greatly through mass production techniques. IoSpan takes a less aggressive approach by using multi-path transmission OFDM or M-OFDM and adaptive array antenna. Their approach is simplified compared to the more aggressive MM systems described in AT&T and BeamReach patents. BeamReach addresses the "overly complex" issue by limiting the use of adaptive antenna and multi-modulation to the base station transmitter while the CPE modem transmits back using TDD. Therefore, the CPE unit takes less processing "horsepower" that results in a lower cost ASIC and antenna assembly. BeamReach claims that because each base station can reach farther and because of massive spectrum reuse, the overall cost per user can be reduced while delivering greater end user throughput. AT&T is apparently aiming their developments directly towards 4G mobile markets. However, they make it clear in their patent descriptions that MM can more easily deliver high rates of spectrum reuse and end user bandwidth for relatively fixed BB applications due to the overhead involved with handing off signals that are spectrally and spatially targeted. "OFDM" is just starting to get going. It remains to be seen if the claims of MM live up to the pioneers expectations. But I believe it is clear that the degree of innovation in the wireless broadband field will be enormous. Cisco recently described the bandwidth gains already seen in the WLAN marketplace: just 18 months ago 1 Mbps was doable and now 11 Mbps is becoming standard. In the near future 54 Mbps will become available.

Report TOU Violation

Share This Post

Public Reply Prvt Reply Mark as Last Read File

Previous 10 Next 10 Previous Next