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Re: [Fsfe-uk] Govt: WiFi does not now infringe Bromcom patent

From: Ralph Janke
Subject: Re: [Fsfe-uk] Govt: WiFi does not now infringe Bromcom patent
Date: Wed, 21 Jul 2004 17:48:49 +0100
User-agent: Mozilla Thunderbird 0.5 (Windows/20040207)

James Heald wrote:

The Government has issued new guidance on the Bromcom patent.

Although claim 7 of the patent was upheld (regarding use of Bromcom's wireless protocol), the Government is advising that WiFi does not infringe, regardless of the software package.

See word file at

Unfortunately, they do not go into details, however I have come to the same conclusion. In studying claim 7 that

1) It is more closely a CSMA/CD (Collision Detection) than CSMA/CA (Collision Avoidance) protocol 2) It has a very specific structure with the central node allowing "free" spaces for the slaves to send 3) There is a very specific topology described around a central node using almost like a hub-star topology 4) Claim 7 only regards attendance data for the collision protocol, no other data is of concern.

In constrast especially when 802.11 is used, I see it very far streched that this could infringe claim 7.

1) 802.11 uses CSMA/CA (Collision Avoidance) which does not seem to fit claim 7 2) In most cases there wouldn't be a central node itself, since the W_Lan is part of the network, not really part of the server 3) There are often total differences in topologies.If i.e someone wants to use W_LAN solely to bridge the network to buildings that aren't connected with cable to the main network, it would be a total different topology than described in claim 7. 4) Most application will have a lot more non-attendance data using the channel than attendance data. None of this data is in any way mentioned in claim 7. How would claim 7 help to stop collisions between such data?

However, saying this, I still do not understand how claim 7 can be upheld in the first place. As more as I look at it, it should be thrown out because of lack of novelty, since it basically describes a 10Base2 protocol. without using a cable. 10Base2 existed already at the time of the patent application, and the protocol itself did not limit itself to a cable. Mostly in such days it the protocols would be described in from of a data channel which can be a lot of things.

Ralph Janke

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