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Technology Stocks : Interdigital Communication(IDCC) -- Ignore unavailable to you. Want to Upgrade?

To: Eric L who wrote (3134)	1/7/2000 12:25:00 PM
From: D.J.Smyth	Read Replies (3) \| Respond to of 5195

Eric. T runs data on TDMA data only lines (also short messaging service on voice lines; has developed directory access, e-mail and list applications too). PDC, whose differences with TDMA are minute, in Japan, is data operative utilizing similar T technology. several LMDS firms now running TDD with data rates up to 10mbps, using same frequency for forward and reverse link; including an overlay for voice. early on TDMA was running fixed data only oines, not unlike GSM. One function that IDC is serving in Japan is to move Nippon and other PDC based TDMA systems from simple SMS to full data capabilities, utilizing packet data technology, at rates of 64kbps (already concurrent) and greater. NTT, DDI, and DDO, all three have PDC TDMA customers - and all three are upgrading their TDMA to be packetized data specific at the same time they are moving toward WCDMA (well, DDI will build out with CDMA2000) full mobile data capabilities with TDMA has also been an issue of spectrum availability (or spectrum assignment under FCC regs) rather than technology. Unlike Europe's GSM, the US under IS-136, did not fully require TDMA to be data functional. it came down to political intrigue (I believe) wherein T didn't want to spend the money for full data capabilities in 1995 (since they held the most sway), even though the technology, as GSM has proven, has always been there. GSM is not really a technology, it is rather a platform upon which all the countries of Europe agreed to build up to. and they did utilizing much of IDC's technology and not paying them for it. of course, 3g specs for new TDD designs are all data specific. the UWCC would certainly take issue with GSM being more robust and evolved that current TDMA spec capabilities. for one GSM continues to have spectrum reuse capabilities (25khz) not as good as TDMA's. one thing that continues to make TDMA attractive is the ubiquitous, low cost seamless transfer from analog to digital. GSM is more involved due to additional layering. It is clear though that Europe, in setting up the GSM standard, utilized IDC's technology in three key areas: (a) frequency hoping capabilities - meaning moving between a transmit, receive, and monitor time slot within TDMA framework (receiving and transmitting currently utilize different frequencies, unlike TDD). The frequency hopping algorithm was IDC's. Multipath fading is dependent on carrier frequency. (b) It was also IDC that perfected what is known as the "burst unit" or period, which defines each TDMA time unit. Generally, eight burst periods are grouped into a TDMA frame. In more current robust TDMA schemes, bursts are increased, thereby increasing the number of users per channel. (c) IDC also helped define the TDMA bursts into specific channels. It was this channel allocation method which IDC used originally to increase the analog capability from 1X to 4X. (d) GSM also uses the Regular Pulse Excited Linear Predictive Coder, for voice modulation and prediction. IDC developed the RPE -LPC, yet they did not acknowledge IDC's claim stake in this way until the German Court decision awarded IDC the claim (as did the Swedish patent court over a dispute with ERICY there). LPCs are better or worse based on quality of result, complexity, cost, processing delay, and power use. From ERICY's own page they explain RPE-LPC's function as being "information from previous samples, which does not change very quickly, is used to predict the current sample. The coefficients of the linear combination of the previous samples, plus an encoded form of the residual, the difference between the predicted and actual sample, represent the signal. Speech is divided into 20 millisecond samples, each of which is encoded as 260 bits, giving a total bit rate of 13 kbps. This is the so-called Full-Rate speech coding." This method is clearly described in IDC patents in the mid and early 80s and is one basis for the fight that IDC is bringing against ERICY. All of ETSI is basically awaiting the ERICY dispute outcome. Some will not take their chances and settle prior to the outcome - as did Nokia; and nearly all the Asian players. We could go on about this. But, needless to say, it is NOT that TDMA is NOT data specific, but rather that many of the carriers or operators have thus far chosen not to make TDMA data specific (relative to need); even though some utilize SMS and data dedicated wireless "lines". Nevertheless, I believe you're referring to packetized data. However, with the advent of the internet and the movement of the internet to countries outside the U.S. where data has not been widely deployed or needed, it is probable that these same countries will upgrade their systems to handle data.