In a previous post we had touched upon briefly on the TenXC patent litigation, where we had stated that the patent at issue was not an essential patent. This post provides an analysis of the patent in issue (Indian patent 240893, hereinafter the 893 patent) in the aforesaid litigation. Before delving deeper into the granted claims of the ‘893 patent, the diagrams and text in the specification support column are from the equivalent PCT application number WO/2007/106989 because the Indian patent office does not make available the formatted text/drawings online. Page numbers in the support column therefore correspond to the PCT application. A copy of the international publication is made available here and a PDF version of this analysis is also made available separately here.
Claim construction
The first step in claim construction is to see whether there is adequate support for the claim text in the specification and drawings in the 893 patent. Amongst the claims, independent claim 1 is first analyzed. Claims 12 and 19 (both independent claims) are reproduced to show similarity to claim 1.
The claims and the support from the specification is provided below in the claim scope section. Our readers may see that the key portion in claim 1 (and claims 12 and 19) mentions that a sector antennae may be replaced by a plurality of split-sector antennae, where at least one (of the plurality) is asymmetrical. Claims 1, 12, and 19 do not define the term asymmetry or say in a precise way how asymmetry is achieved. The specification does provide concrete examples of achieving asymmetry with active/passive networks with or without antenna arrays; and use of power and phase coefficients to generate a desired pattern (highlighted in red in the table below). Therefore, claim 1, and similarly claims 12 and 19 are broad according to the statute under section 10(5)-which provides that claims shall be clear and succinct and fairly based on the matter disclosed in the specification.
One possible way to overcome this issue is to include the limitations of the dependent claims in the independent claim. This would narrow the independent claim and include the limitation from any of the dependent claims, for example, claim 8-11 that specify how asymmetry is to be achieved.
Our more informed readers would know that an equivalent counterpart application (12/094299) in the United States with claims very similar to that of the granted Indian application has been given a non-final rejection under sections 102(a) and 103. A copy of the US office action is made available here.
It seems that this patent got exceptionally lucky while undergoing prosecution at our IPTO as only one office action (First examination report) was issued where only a few minor objections with respect to dependent claims were raised!! All I can say is that the examination should have been more rigorous.
Claim scope determination
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Claim
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Specification Support
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1. A method for increasing subscriber capacity in a sectorized cellular communications network having a plurality of subscribers and a base station supporting at least one sector, each of the at least one sector having one or more associated sector antennae at the base station having a critical coverage area extending therefrom and overlapping neighbouring sectors thereof in a sector handover zone, the method comprising the step of:
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In the present invention, rather than dealing with an increase in capacity by prior art mechanisms such as higher-order sectorization and/or cell splitting, an existing antenna is substituted with a new one, which has substantially the same coverage area as the fixed cell sector being replaced, but divided into a plurality of complementary asymmetrical separate beams or sub-sectors. Page 9, lines 4-10.
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replacing the associated one or more sector antennae for a given sector with a split-sector antennahaving a plurality of sub-sector coverage areas extending therefrom, at least one of which is asymmetrical,
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Where, as with the present invention, the new antenna may produce a plurality of separate beams, each defining a new sub-sector with only a small overlapping area between them and which together provide substantially identical coverage to the sector supported by the.original antenna, a single sector may be upgraded to become a plurality of sub-sectors without significantly affecting neighbouring sites.
It has been discovered that such new antennas may be created by introducing asymmetry into the generated beam pattern.
Page 9, lines 24-Page 10, line 3
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each corresponding to a sub-sector and overlapping a neighbouring sub-sector coverage area in a sub-sector handover zone, whereby a total critical coverage area provided by the plurality of sub-sector coverage areas is substantially equivalent to the critical coverage area of the replaced one or more associated sector antennae.
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As can be seen from a comparison of Figure 2, which shows 3 mirror-imaged pairs (210, 211), (220,221), (230,231) of asymmetrical sub-sector beams to replace a traditional 3 sector configuration with a 6 sub-sector configuration, the use of asymmetrical beams ensures handover region reduction by means of the low overlap 212 of adjacent pairs of sub-sector beams 210, -211 and between sub-sector beam 211 of a first pair and a sub-3 sector beam 220, of a second pair, shown at 223. This consequently reduces handover overhead for most wireless standards and results in a net capacity and throughput increase, while maintaining the initial coverage by matching the antenna radiation pattern at the edges of the original sector, so that network planning overhead is minimized or avoided. Furthermore, the use of an asymmetrical sub-sector beam maintains low cusping loss between adjacent beams so as to achieve good overall network coverage with no new coverage holes. This is shown in Figure 3 which shows, for clarity of illustration, sub-sector beams 230, 231, overlaying conventional full sector beam patterns 310, 320, 330 shown in dashed outline.
Page 10, line 24-Page 11 line 11.
In a preferred embodiment, the asymmetrical beams are implemented using antenna arrays in conjunction with passive and/or active networks. However, those having ordinary skill in this art will recognize that it is possible to implement the inventive asymmetrical beam patterns without resort to antenna arrays.
Page 13, lines 26-31.
Those having ordinary skill in this art will appreciate that there are a number of mechanisms by which a series of powers and phase coefficients could be generated to match a specified antenna pattern, including but not limited to array synthesis methods, solving constrained optimization problems or even by trial and error. In this instance, a simulation tool, such as is available from Zeland Software Inc. was used to predict the asymmetrical antenna array patterns and the expected array performance obtainable therefrom.
Page 15, lines 1-10.
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Figures 2 vs. Figures 3
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12. A split-sector antenna for use in a sectorized cellular communications network having a plurality of subscribers and a base station supporting at least one sector, each of the at least one sector having one or more associated sector antennae at the base station having a critical coverage area extending therefrom and overlapping neighbouring sectors in a sector handover zone, the split-sector antenna being constructed and arranged for replacing the one or more associated sector antennae and having a plurality of sub-sector coverage areas extending therefrom, at least one of which is asymmetrical, each corresponding to a sub-sector and overlapping a neighbouring sub-sector coverage area in a sub-sector handover zone, whereby a total critical coverage area provided by the plurality of sub-sector coverage areas is substantially equivalent to the critical coverage area of the replaced one or more associated sector antennae.
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19. A sectorized cellular communications network having a plurality of subscribers, comprising:
one or more base stations each supporting at least one sector; and
a sector antenna associated with each of the at least one sector providing a critical coverage area extending therefrom and overlapping neighbouring sectors in a sector handover zone, at least one said critical coverage area comprising an asymmetrical coverage area.
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You are not discussing the prior art at all. A claim can be as broad as possible unless for a prior art.
Sec 10(5) requires the claims to be fairly based on the specification, which this claim is. Why does it have to be limited, just because the specification provides for it. Why should one amend claim 1 to include how asymmetric is done and limit the scope of claim, if prior art does not talk about it?
You can see that the claims have received a 102(a) and a 103 rejection at the USPTO.
The whole issue is there because prior art squarely covers different ways of providing asymmetry.
Asymmetry may be achieved by different methods-would all possible ways of asymmetric communication infringe on this claim? Yes if you by your logic, which is incorrect. Hence one needs to limit the scope of this over broad claim.
In India the patent examination is not very strict as in USPTO Patents are granted if they meet minimum standards and this is why we find most patent oppositions or revocations to be allowed and patents revoked. The problem is Indian Patent Office revokes a patent even if one claim is defeated.
What is the latest development in this case?