|Title of Invention||
"A WIRELESS LOCAL AREA NETWORK TRANSCEIVER"
|Abstract||This invention relates to a wireless local area network transceiver wherein the transmit path consists of transmit stream (1), shift register (17), selector (18) characterized by bootstrapped direct sequence generator (16) to enable seamlessly transit from a preamble spreading sequence to a direct sequence derived from a label in the preamble, a switch (19), spreader (20), radio circuits (24, 25) and controller (23) for interfacing with host machine and receive path consists of data stream (10), shift register (21) and associative memory (22).|
|Full Text||FIELD OF INVENTION
This invention relates to wireless local area network transceiver with bootstrapped direct sequence spread spectrum multiple access for packet data communication.
Wireless local area networks (WLAN) even when they use spread spectrum technology do not use the multiple access capability. When a section A talks to station B, the absence of multiple access capability prevents another station C from communicating with D. Direct sequence spread spectrum (DSSS) has been used in the physical layer for WLAN in the ANSI/IEEE 802.11 standard. However, a limitation of above is that multiple access capability of DSSS, known as spread spectrum multiple access (SSMA), is not used.
The widely used ANSI/IEEE 802.11 standard specifies the same 11-chip barker sequence as the spreading code to be used by all 802.11 cards.
The single spread spectrum channel on an ANSI/IEEE 802.11 WLAN is used by multiple users by a combination of coordinating functions including carrier sense multiple access/collision avoidance (CSMA/CA).
Bluetooth system is known to be used in short range radio for connecting devices like keyboards and three-in-one phones, to use frequency hopping spread spectrum. However, blue tooth system has also the limitation that it does not use the multiple access capability. Only the frequency hopping sequence is used in a subnet, that of the master of the subnet. While this architecture is sufficient for small subnets with a few devices, it has the drawback that it leads to performance bottlenecks when there are many devices and the communication is between these devices and not centralized to a master and its slaves.
OBJECTS OF THE PRESENT INVENTION
The principal object of this invention is a WLAN means that uses boot strapped direct sequence for SSMA below CSMA/CA.
STATEMENT OF INVENTION
According to this invention there is provided a wireless local area network transceiver wherein the transmit path consists of transmit stream, shift register, selector characterized by bootstrapped direct sequence generator to enable seamlessly transit from a preamble spreading sequence to a direct sequence derived from a label in the preamble, a switch, spreader, radio circuits and controller for interfacing with host machine and receive path consists of data stream, shift register and associative memory.
DESCRIPTION OF FIGURES
The invention is illustrated with the help of accompanying drawings which illustrates an embodiment of the present invention is not intended to be taken restrictively to imply any limitation thereto. In the figure, a thin solid line indicate a path for a date bit stream, a dashed line indicates a control path consisting of one or more signal lines and a thick solid line indicates a path for a data vector of several bits. In the accompanying drawings.
Fig. 1 shows the wireless local area network means with bootstrapped direct sequence spread spectrum.
DESCRIPTION OF DRAWINGS w.r.t. DRAWINGS
The main component of the wireless local area network (WLAN) is the bootstrapped direct sequence generator (16). The transmit path consists of transmit stream (1), a shift register (17), selector (18), switch (19) and spreader (20). The receive path consists of data stream (10), shift register (21), associative memory (22). Controller (23) decides the mode of the transceiver and sets up internal data paths. These components are connected together as shown in fig. 1. A WLAN means consists of radio circuits (24,25) for the air interface and a controller (23) for interfacing the card with the host machine.
METHOD OF WORKING
Normally WLAN is in receive mode. When the upper layer wants to transmit a packet, it handshakes with the WLAN means. If it is not
already in the middle of a reception, the transmit request is granted and the means switches to transmit mode.
The bootstrapped direct sequence generator (16) enables seamlessly transit from a preamble spreading sequence to a direct sequence derived from a label in the preamble. Bootstrapped direct sequence generator (16) will generate the preamble spreading sequence at its output when reset on (13). When a label is presented on (4) bootstrapped direct sequence generator (16) will seamlessly generate a DS derived from that label.
In the bootstrapped direct sequence format, a packet is not spread using a single DS. The preamble of a packet is spread using a preamble spreading sequence and the rest of the packet is spread using the DS derived from the SSMA channel label. The preamble contains the SSMA channel label.
When the host machine wishes to transmit a packet, it signals the intention to transmit on signal line (2). If the transceiver is not in the
middle of a reception, radio circuit (24) will change the mode of the transceiver to transmit. Radio circuit (24) will instruct the switch (19) on (5) to direct the output of the DS generator (16) to the spreader (20) on (7). Controller (23) will also instruct the selector (18) on (14) to select shift register (17) for presenting as (4). Controller (23) will reset selector (16) through (13), making it ready to generate DS as the preamble spreading sequence. After DS generator (16), selector (18) and switch (19) have been instructed, controller (23) will signal the host machine on (2) that it can commence transmission on transmit stream (1). The first bit of packet data on transmit stream (1) will initiate the clocking of DS generator (16). The preamble of the packet consisting of synchronization bits and the destination address will be shifted into the spreader (20), and spread using the DS on (7). The spread transmit signal will be presented to the radio section on (3) for modulation, power amplification and transmission as air waves. When the transmit bits are being shifted in, they are moved to the shift register (17) in parallel. When the destination address of 48 bits is in shift register (17), the selector (18) that was instructed to present shift register (17) as (4) will do so.
When DS generator (16) receives the destination address in shift register (17) as the channel label at (4), it will stop generating the DS and seamlessly switch to generating the DS derived from the destination address. Thus the rest of the packet frame will be spread using the DS on (7) generated by DS generator (16) from the destination address.
The controller (24) instructs switch (19) on (5) to switch its input from DS generator (16) to signal path (8). The controller (24) readies DS generator (16) on (13) to generate DS. The direct sequence (8) is used by the radio receiver section to synchronize and despread the received radio signal. Thus the WLAN means is in receive mode with the DS as the Preamble Despreading Sequence. The radio section returns indication of receiver code synchronization on signal path (9). Absence of synchronization will be used to slip DS generator (16). When the dispreading direct sequence (8) aligns with the spreading DS in the received signal, it will be indicated by the signal on (9). When DS generator (16) is synchronized, it need not be slipped further.
After synchronization, the despread frame data on (10) from the radio section is shifted to the register (21). After the 48 bits of the destination
address in the frame have been shifted into register (21), it will be sent to the associative memory (22) which contains the broadcast address and the MAC address of the WLAM means, if register (21) is in associative memory (22) signal on (11) will be sent to the controller (24) which will instruct selector (18) on (14) to lock the matching address in associative memory (22) as (4). When DS generator (16) gets the address from associative memory (22) as the channel label on (4), it will switch from generating the DS to the DS derived from the address in the received frame. The new DS will be used by the radio section to despread the rest of the frame. The register (21) will be used as a FIFO of the received data (10). It will be shifted to the host machine of the WLAN means as the received data (15). If register (21) is not in associative memory (22), it will be indicated to controller (24) on signal path (11). Controller (24) will reset the direct sequence generator (16) on (13) so that the WLAN means aborts reception of the current frame and starts looking for a new frame. Resetting of the DS on (8) will cause the radio section to lose synchronization. The radio section will signal on (9) that synchronization has been lost. Register (21) will be emptied on this transition of thestrength signal (9). Thus only frames meant for this WLAN means will be passed to the host.
By this invention, SSMA is enabled below CSMA/CA and so performance is improved when the network traffic is high or when several pairs of stations communicate among themselves. Further transceiver with a single direct sequence generator and a single spread spectrum receiver is able to operate on half duplex mode and receive both broadcast frames and frames addressed specifically to the WLAN. It can also receive multicast addressed frames if the multicast addresses are loaded into its associative memory.
It is to be noted that present invention is susceptible to modifications changes and adaptations by those skilled in the art. Such, variant embodiments incorporating the concepts and features of the present invention, are intended to be within the scope of the present invention, which is further set forth under the following claims:
MOST RESPECTFULLY SHEWETH:-
In connection with the referenced application and an interview at the Patent Office on April 28, 2009, the applicant has been advised that certain earlier objections from the First Examination Report have been maintained, and also that certain fresh objections have now been raised by the learned Examiner. In connection therewith, the applicant respectfully presents the following further submissions.
In the First Examination Report dated April 29, 2008 and subsequent verbally communicated objections dated April 23, 2009 and April 28, 2009, the learned Examiner has expressed the view that subject matter of the present application does not satisfy the definition of "invention" as provided under Section 2(l)(j) of the Patents Act, 1970, particularly in view of prior art references JP 2003-532003 (Dl -reflected as a document of relevance in the findings of the ISR) and in view of WO 00/33511 (D2) and US 2002/132,611 (D3) (both of which are reflected as documents of relevance among the findings of the EPO on corresponding EP application 04 726 799.2.
The learned Examiner has thereafter expressed the view that claims 1 to 12 (which recite an apparatus) are in fact directed towards software, and are accordingly precluded from patentability under Section 3(k) of the Patents Act.
It is respectfully submitted that the applicant's invention is novel, inventive and capable of industrial applicability and accordingly satisfies the various criteria provided under Section 2(1 )(j) of the Patents Act, 1970 (the Act). It is further submitted that the system of claims 1 to 12 of the referenced application are not
directed towards "computer programs per se" and the statutory preclusion under Section 3(k) of the Act therefore does not preclude grant of a patent on the subject application. The applicant sets out in seriatim hereinbelow, detailed grounds on which the claimed invention satisfies the statutory requirements of the Act.
Test for Novelty
To anticipate or destroy novelty in an invention, a prior art reference must disclose the whole of the claimed invention, that is all the features by which the claim under attack has been limited (Allmanna Svenska Elehtriska AB v. Burntisland Shipbuilding Co. Ltd. (1952) 69 RPC 63 at 68).
As held by the Hon'ble High Court of Delhi in Raj Parkash v. Mangat Ram Chowdhry and Ors. (AIR 1978 Del 1), where what is claimed is a combination of integers so placed together that by their working interrelation they produce a new or improved result, the claim is not anticipated merely because the separate integers are old.
A claim to a combination of integers cannot be shown to lack novelty by finding part of the combination in one prior art document and part in another (Martin and Biro Swan Ltd. v. Hillwood Ltd. (1956) RPC 125 at 138). The test to be applied is whether that combination of integers has been disclosed in a single prior art reference.
The invention of claims 1 to 12 is a communication system for achieving end-to-end Quality of Service (QoS) in a mobile network, comprising a terminal with QoS control module that is capable of performing QoS monitoring, reporting and enforcement, a central controller that accepts QoS reports from the terminal, gives QoS enforcement
instructions to the terminal and performs QoS management based on the QoS records from the terminal and its subscription information. The terminal of the communication system collects QoS information, which is QoS measurement at each of the terminal's running applications, reports the collected QoS information to the central controller, receives enforcement instructions from the central controller, and regulates a behavior of the terminal according to metrics received through a communication module. Further, said terminal is capable of dynamic discovery of the central controller and establishment of a connection with the central controller.
It is respectfully submitted that none of the cited prior art documents disclose the above combination of features, and therefore cannot be held to anticipate subject matter of claims 1 to 12.
At the outset, it is respectfully submitted that the documents Dl, D2 and D3 were cited in the ISR and by the EPO in connection with claims as they stood in international phase. As the learned Controller would observe, claims of the international application have been amended in the course of prosecution of the Indian application, in response to the objections raised by the learned Examiner. Amended claims 1 to 12 now recite the following additional features which were not considered by the ISA and EPO when citing documents Dl to D3:
• The terminal of the communication system collects QoS information, which is QoS measurement at each of the terminal's running applications, reports the collected QoS information to the central controller, receives enforcement instructions from the central controller, and regulates a behavior of the terminal according to metrics received through a communication module; and
• Said terminal is capable of dynamic discovery of the central controller and establishment of a connection with the central controller.
Documents Dl and D2
It is respectfully submitted that documents Dl and D2 both relate to the same disclosure, in that Dl (JP 2002-532003) is the Japanese national phase application corresponding to D2 (international application WO 00/33511). The applicant's submissions regarding D2 hereinbelow accordingly apply equally to Dl.
Document D2 discloses an arrangement and method for improving QoS for a communications network, wherein the endpoints and routers of the prior art system can collect link parameters and device parameter measurements, make end-user QoS measurements, and send appropriate reports to a service quality supervisor. Reference to embodiments of the invention disclosed in Dl indicate that the device parameters relate to parameters measured for the device as a whole, and link parameter relate to parameters relating to the data link provided by the packet-switched network.
As the learned Controller would observe, said document does not disclose the technical feature wherein the terminal of the communication system collects QoS information comprising QoS measurements from each of the terminal's running applications, which technical feature comprises an essential limitation of amended claims 1 to 12.
Said technical feature of the claimed invention may be understood with reference to relevant portions of the specification wherein it is disclosed that collection of QoS information which is QoS measurement at each of the terminal's running applications is implemented by monitoring module 1103 (metering module 1102) of the QoS controller 1110 (see Figure 11 of the specification). Monitoring module 1103 includes metering module 1102 for collecting performance monitor data (i.e. QoS information at an application, e.g. band usage at a video encoder application) as described on page 37 lines 13 to 15, whereafter the communication module 1110 collects performance monitoring data such as QoS measurements from metering module 1102 and reports them to the SLA manager 1111 from reporting module 1109 (as described on page 37 lines 18 to 24).
Providing for measurement of QoS information at each of the terminal's running applications presents several advantages including allowing the terminal to dynamically address QoS requirements of applications running simultaneously therein, with due regard to issues of data congestion, priority levels, and bandwidth requirements among the various running applications.
In addition, documents Dl and D2 also do not disclose the feature or the manner in which the terminal of the claimed system is capable of dynamic discovery of a central controller and establishment of a connection with said controller.
In view that documents Dl and D2 do not disclose, teach or suggest a system having the two key limitations of amended claim 1, said documents do not anticipate the applicant's invention.
D3 (US 2002/0132611) discloses a method and network for assigning values of service attributes to transmissions between a user-equipment and a radio access network. With a view to allow for assigning of appropriate QoS values to transmissions between a user equipment and a radio access network, the cited document provides for a system wherein QoS values are determined based on at least one service attribute defined by a stored subscriber profile, and at least one stored common value of a service attribute. Essentially, the system and method disclosed in D3 require at least two pre-determined (and pre-stored) values, the first reflecting the subscription profile of the subscriber device, and the second reflecting a pre-determined (and pre-stored) value commonly associated with the requested transmission service. Accordingly, the invention of document D3 differs from the applicant's invention in three critical aspects.
First, the invention of D3 requires determination of QoS based on pre-determined values, as opposed to determination based on dynamic (real time) terminal measurement of QoS metrics. As the learned Controller would observe, the applicant's invention does not lie in storage of pre-determined values, nor does QoS monitoring and enforcement depend critically on such pre-defined values. Instead, the claimed invention rests on QoS monitoring and enforcement within the end-user terminal by collecting QoS information comprising QoS measurements at each of the terminal's running applications.
Second, the system and method of D3 require a QoS determination to take place each time a transmission is sought to be initiated with an end-user device, wherein the determination of QoS values is a pre-condition to the transmission request being
granted. The prior art document therefore does not contemplate an on-going monitoring of a plurality of applications running within the terminal, wherein changing QoS metrics can affect transmission parameters at any stage during a transmission.
Third, document D3 also does not disclose the limitation of claim 1, wherein the terminal is capable of dynamic discovery of the central controller and establishment of a connection therewith.
In view of the applicant's above submissions, it is respectfully submitted that subject matter of the claimed invention is not anticipated by any one of documents Dl to D3, as none of the three cited references, either taken by themselves or in combination with each other disclose the specific limitations recited in the claimed invention, nor seek to achieve the specific technical objective that the applicant's invention addresses.
Test of Obviousness
It is respectfully submitted that the applicant's invention is also inventive and non-obvious.
While the learned Examiner has for the time being not referred to a further document cited by the EPO i.e. "Real-time Application Quality of Service Monitoring (RAQMON) Framework
respectfully submits that disclosure in the cited document is significantly removed from the claimed invention as well.
D4 discloses a system that allows collection of QoS parameters, and forwarding such parameters to a network entity, and also defines the QoS parameters of relevance and the transport mechanism. The learned Controller would however observe that D4 does not provide any indication or disclosure to the effect that the terminal either receives QoS enforcement instructions or regulates behavior of the various applications running at the terminal. In addition, D4 also does not provide any teaching or suggestion that the network entity has any functions corresponding to that of the central controller (of the applicant's invention), wherein the Controller provides QoS enforcement instructions to the terminal and performs QoS management based on QoS records from the terminal and its subscription information.
It is also respectfully submitted that the goal of the applicant's invention (of providing a system for end-to-end QoS within a mobile network) is completely different from the purely statistical data collection objective of document D4.
It is submitted that whether an invention is obvious or not has been the subject of several landmark decisions. The critical principles and tests laid down in some of the important decisions have been provided hereinbelow for the learned Controller's reference.
Section 2(l)(ja) of the Patents Act, defines "inventive step" as a feature of an invention that involves technical advance as compared to the existing knowledge or having
economic significance or both and that makes the invention not obvious to a person skilled in the art.
In Windsurfing International Inc. v. Tabur Marine (Great Britain) Ltd., (1985 RPC 59 at 73-74) the following principles have been established for a determination of obviousness:
1. Identify the inventive concept embodied in the invention.
2. Assume the mantle of a normally skilled but unimaginative addressee in the art at the relevant date and impute to him what was at that date, common general knowledge in the art in question.
3. Identify the differences between the prior art and the alleged invention.
4. Whether, when viewed without any knowledge of the alleged invention, those differences would constitute steps that would have been obvious to the skilled person, or whether they required any degree of invention.
In order to establish that a claimed invention is obvious, some motivation must be shown to demonstrate that a person of ordinary skill in the art and with no knowledge of the claimed invention, would modify the teachings of the prior art references to arrive at the claimed invention. Thus, even where every element of a claimed invention may be found in prior art, identification of each individual part is insufficient to defeat patentability of the claimed invention as a whole (In re Rouffet, 149 F. 3d 1350, 1357 (Fed. Cir. 1998)).
As held in Siddell v. Vickers & Sons Ltd., 1890 RPC 292 at 304, if the apparatus be valuable by reason of its simplicity, there is a danger of being misled by that very
simplicity into the belief that no invention was needed to produce it. However, experience shows that not a few inventions ... have been of so simple a character that once they have been made known, it was difficult... not to believe that they must have been obvious.
Further, the apparent simplicity of the invention, or the ease with which said invention is understood, should not cause an examiner to fall victim to the insidious effect of hindsight syndrome, wherein that which only the invention taught is used against the teacher (In re Kotzab, 217 F.3d 1365 1369 (Fed. Cir. 2000)).
Even when obviousness is based on a single prior art reference, there must be a showing (in that reference) of a suggestion or motivation to modify the teachings of that reference (B.F. Goodrich Co. v. Aircraft Braking Sys. Corp., 72 F.3d 1577, 1582 (Fed. Cir. 1996)).
Even a prima facie application of the above tests makes it apparent that the claimed invention is inventive over disclosure in the prior art.
It is submitted that the claimed invention satisfies the definition of "inventive step" under Section 2(l)(ja). The novel and inventive features of the claimed invention are the features wherein the end-user terminal of the claimed system measures and collects QoS information at each of the running applications within said terminal, and also that the terminal is capable of dynamic discovery of the central controller and establishment of a connection with said controller, with a view to provide integrated and end-to-end QoS management within a network. It is respectfully submitted that
this combination of features is neither disclosed nor suggested by any of the cited documents Dl to D3, nor document D4 which has been subsequently cited at the EPO.
It is therefore respectfully submitted that the applicant's invention is inventive over prior art and accordingly merits grant of a patent.
In view of the above, it is respectfully submitted that the claimed invention satisfies the tests of novelty and inventive step required by Section 2(1 )(j) of the Act.
Objection under Section 3(10 of the Patents Act
Objections raised in the First Examination Report and subsequently reiterated by the learned Examiner indicate the view that despite claims 1 to 12 being directed towards a system, said claims would nevertheless be precluded under Section 3(k) of the Patents Act. It is respectfully submitted that a finding that system claims 1 to 12 of the referenced application are precluded from patentability under Section 3(k) is not only ultra vires the scope of the statute, but is also completely contradictory to the intention and objective thereof.
Section 3(k) of the Act inter alia precludes patentability of computer programs per se. The term "per se" is understood to mean "by itself, and the preclusion under Section 3(k) is therefore intended to apply to claims directed towards computer programs by themselves i.e. to claims which recite computer programs, and computer software, and to instructions embodied in software code without any tangible character or technical effect, and which do not have any consequences in a technical field outside the confines of the machine executing such instructions. Said preclusion by
necessity cannot be extended to include any and all inventions that either have applications within the field of computing devices, or that are computer implemented. To interpret Section 3(k) in this broad manner would essentially lead to dismissal of the statutory limitation "per se", which dismissal would be ultra vires the powers granted under the Patents Act.
As the learned Controller would observe, the system claims of the applicant's invention are directed towards a means for achieving a desirable, useful and tangible result within a technical field (i.e. heterogeneous mobile communication networks), which system has utility in industry.
The system claimed by the applicant is therefore immediately distinguishable from computer programs per se on the following grounds:
• That the claimed system telates to a technical field, namely that of radio communication systems a|nd wireless technology within mobile networks. Said system demonstrates a technical and tangible effect within said field i.e. providing end-to-endj QoS guarantees within the network, thereby ensuring that data delivery within the network is timely, and in particular in connection with systems and applications that are delay sensitive.
• That in addition, the claimed communication system has been recited in terms of specific hardware/machine limitations, including terminals, QoS control modules, central controllers, communication modules, and in certain preferred embodiments, other limitations including subsystems for policy control and for security control. It is respectfully submitted that said
hardware/machine limitations make it apparent that the claimed system and methods possess the technical effect necessary to distinguish claimed subject matter from a computer program per se (i.e. a mere sequence of instructions embodied in software code) and that the system demonstrates tangible technical effect beyond the immediate scope of the machine executing such instructions. Even by the most lenient principles of statutory interpretation, the system claims of the applicant's invention cannot therefore be understood as a computer programmer se.
In view of the applicant's submissions hereinabove, it is respectfully submitted that the system claims of the referenced application are not precluded from patentability under Section 3(k) of the Patents Act. The learned Controller is therefore respectfully requested to set aside the objection in connection therewith.
In view of the above, it is respectfully submitted that the claimed invention comprises appropriate subject matter for a patent. The learned Controller is accordingly respectfully requested to set aside the objections raised by the learned Examiner and to grant a patent on the application at the earliest.
Yoursincerely, Nitin Masilamani
|Indian Patent Application Number||1509/DEL/2003|
|PG Journal Number||23/2009|
|Date of Filing||03-Dec-2003|
|Name of Patentee||DEPARTMENT OF INFORMATION TECHNOLOGY|
|Applicant Address||MINISTRY OF COMMUNICATIONS & INFORMATION TECHNOLOGY, GOVERNMENT OF INDIA, ELECTRONICS NIKETAN, 6 C.G.O. COMPLEX LODHI ROAD, NEW DELHI-110003|
|PCT International Classification Number||H04L 12/00|
|PCT International Application Number||N/A|
|PCT International Filing date|