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Technology Stocks : Ericsson overlook? -- Ignore unavailable to you. Want to Upgrade?

To: P2V who wrote (2193)	10/24/1998 12:03:00 AM
From: JGoren	Respond to of 5390

I am posting this from the Qualcomm thread, because I think this post by Clark, Hare most clearly describes the patent issue on soft handoff as far as identifying the steps of handoffs, the choices of methods and where (if at all) there is a conflict: >>> To: +Dave (17066 ) From: +Clark Hare Friday, Oct 23 1998 10:26PM ET Reply # of 17086 Dave - The Ericsson patent for soft hand-off (5109528) was filed 6/13/98. As for the question of the validity of the patent to CDMA, my argument about Qualcomm having documentation that invalidates it for CDMA is: 1) It is almost certain that there are some published papers from before 1989 which discuss spread spectrum cell systems. Any such papers are almost certain to discuss frequency reuse as it is the primary motivating factor for such a system. 2) Qualcomm almost certainly had discussions with Ericsson about their goals inre CDMA cell systems. It may not have been public knowledge, but Ericsson would have known as part of Qualcomm intentionally telling them. (I was trying to look up case law on what qualifies as 'knowledge', especially in regards to a non-disclosure agreement, but it is probably moot since the non-disclosure is after the filing date.) Clark PS As for the reason why the Ericsson patent is 'obvious': 1) When designing a cell system, there are really on two choices when a user moves from cell to cell. The message channels are changed (hard handoff), or they aren't (soft handoff). Prob=0.5 2) In any handoff, it is necessary to prevent the two basestations from over-writing each other's control traffic. This can be done either by having the mobile use two separate channels for control, or by making sure that they aren't broadcasting at the same time. The Ericsson patent assumes different times (and gives no specific direction on how this is to be done - 'and then a miracle happens'.). Prob = 0.5 3) In soft handoff it is necessary to make sure that the two basestations do not broadcast at the same time or that they use different keys. Prob = 0.5 The conclusion is that at the level of detail which Ericsson gives there are only a few ways to build a cell system, and the thing Ericsson tried to patent is 1/8 of them. Thus my statement that it is obvious. (Note that most of the patent is spent giving background on cell systems and how to determine when handoff should occur, but they note that this is not the part that is to be patented.) >>>>