The present invention relates to communication systems. More particularly, binding a plurality of communications channels to realize an aggregate throughput improvement is disclosed. The binding feature may be added in a manner that preserves compatibility with existing standards-based wireless data systems.
Existing digital wireless communication systems communicate on a single RF channel, as shown by a prior-art standards-compliant client transceiver 120 in
Although technological advances have increased the available digital throughput for any particular assigned frequency channel in a given band, there is always a desire to send data ever more rapidly or with greater integrity than can be accommodated with the single-channel approach. Thus, there is a need in the art for a method and apparatus for binding a plurality of data channels together to achieve aggregate throughput improvement including data rate and/or data integrity improvement.
Various embodiments of the invention are disclosed in the following detailed description and the accompanying drawings.
The invention can be implemented in numerous ways, including as a process, an apparatus, a system, a composition of matter, a computer readable medium such as a computer readable storage medium or a computer network wherein program instructions are sent over optical or electronic communication links. In this specification, these implementations, or any other form that the invention may take, are referred to as techniques. In general, the order of the steps of disclosed processes may be altered within the scope of the invention.
A detailed description of one or more embodiments of the invention is provided below along with accompanying figures that illustrate the principles of the invention. The invention is described in connection with such embodiments, but the invention is not limited to any embodiment. The scope of the invention is limited only by the claims and the invention encompasses numerous alternatives, modifications and equivalents. Numerous specific details are set forth in the following description in order to provide a thorough understanding of the invention. These details are provided for the purpose of example and invention may be practiced according to the claims without some or all of these specific details. For the purpose of clarity, technical material that is known in the technical fields related to the invention has not been described in detail so that the invention is not unnecessarily obscured.
This arrangement of channels is advantageous because when pairs of channels equally offset from a center frequency are operated contemporaneously, undesirable artifacts of the modulation of one channel upon a carrier are manifested in an equally but oppositely displaced, occupied channel. These artifacts might otherwise require expensive suppression to meet the requirements of, for example, the wireless data communications standard IEEE-802.11a. These artifacts are of less importance in prior-art single-channel systems or in the single master channel in some embodiments.
Packet generators 312, 314 and 316 packetize data in each channel in an appropriate manner. In some embodiments, packetizing is implemented as is described in the IEEE-802.11a standard. IFFT processors 322, 324 and 326 similarly process the packetized data into baseband encoded signals 323, 325 and 327, respectively. Baseband signals 323 and 327 comprise the secondary channel signals and are up converted and down converted by mixers 332 and 334 using complex carriers 332333 and 335 respectively, carriers 332333 and 335 having a frequency equal to the RF band channel spacing. Muxes 340, 342 and 344 allow selective passage of the baseband signals from each chain to summer 348. The output of summer 348 feeds a digital baseband signal to analog converter (DAC) 350. The baseband output of DAC 350 is mixed by mixer 336 with a local oscillator signal 336356 whose frequency places the output signal on a selected channel of a chosen RF band.
Packet generator 314 is associated with the master channel and generates beacons in a manner substantially as described by existing standards such as IEEE-802.11a. The beacon generation in the packet generators 312 and 316 associated with the secondary channels is disabled by the device driver in some embodiments.
Power amplifier 354 boosts the mixed signal to a level suitable for transmission. Selectable bandpass filter (BPF) 360 is, in one embodiment, set to a single-channel width when only the master channel is active and a three-channel width when two adjacent secondary channels are active. Mux 346 allows selective passage of baseband signal 325 to mixer 338, which mixes the output of mux 346 with a local oscillator signal 358 whose frequency places the output signal on another selected channel of the chosen RF band. Power amplifier 354 boosts the mixed signal to a level suitable for transmission. In a dual-band embodiment, power combiner 362 combines the output of power amplifier 352 and BPF 360 to feed antenna 114.
The chain of processing from data stream 301 through the output of DAC 350 represents a baseband encoder chain. The chain of processing from the input of mixer 336 to the antenna 114 represents an upconverting transmitter chain.
Reception of bound streams is performed by hardware symmetric in function to the encoding described above; data is received on a master channel and one or more secondary channels, with data receivers replacing transmitters, FFT blocks replacing IFFT blocks and a data combiner replacing the data distributor.
When an access point transceiver and a client transceiver seek to communicate, the client, in accordance with existing standards and practice, would listen for a beacon signal from the access point and then enter into an exchange that establishes an association. An example of the association process is to described in §11.3 of the IEEE-802.11-1999 standard. Various extensions of the association process allow for vendor-specific features to be advertised to and accepted by a client device (for example, Atheros Communications' existing “Turbo Mode”). The channel binding feature is similarly treated as another form of vendor-specific extension to the association process.
The present invention has been described above in connection with a preferred embodiment thereof; however, this has been done for purposes of illustration only, and the invention is not so limited. Indeed, variations of the invention will be readily apparent to those skilled in the art and also fall within the scope of the invention.
Although the foregoing embodiments have been described in some detail for purposes of clarity of understanding, the invention is not limited to the details provided. There are many alternative ways of implementing the invention. The disclosed embodiments are illustrative and not restrictive.
Number | Name | Date | Kind |
---|---|---|---|
4412325 | Molo | Oct 1983 | A |
4912422 | Kobayashi et al. | Mar 1990 | A |
5031207 | Hesdahl et al. | Jul 1991 | A |
5191410 | McCalley et al. | Mar 1993 | A |
5592470 | Rudrapatna et al. | Jan 1997 | A |
5592490 | Barratt et al. | Jan 1997 | A |
5689568 | Laborde | Nov 1997 | A |
5692126 | Templeton et al. | Nov 1997 | A |
5781598 | Hardy, III | Jul 1998 | A |
5856999 | Robinson et al. | Jan 1999 | A |
6118796 | Best et al. | Sep 2000 | A |
6154659 | Jalali et al. | Nov 2000 | A |
6335927 | Elliott et al. | Jan 2002 | B1 |
6480494 | Hawley | Nov 2002 | B1 |
6539209 | Dajer et al. | Mar 2003 | B1 |
6563820 | Griess | May 2003 | B1 |
6601234 | Bowman-Amuah | Jul 2003 | B1 |
6671500 | Damgaard et al. | Dec 2003 | B2 |
6751772 | Kim et al. | Jun 2004 | B1 |
6873630 | Muller et al. | Mar 2005 | B1 |
6918135 | Goffin, II | Jul 2005 | B1 |
7002911 | Linville et al. | Feb 2006 | B1 |
20020116460 | Treister et al. | Aug 2002 | A1 |
20020197998 | Schmidt | Dec 2002 | A1 |
20030035388 | Schmidt | Feb 2003 | A1 |
20060095581 | Ali et al. | May 2006 | A1 |
Number | Date | Country |
---|---|---|
1357179 | Oct 2000 | CN |
63108825 | May 1988 | JP |
7066739 | Mar 1995 | JP |
7202758 | Aug 1995 | JP |
2001320346 | Nov 2001 | JP |
2003528527 | Sep 2003 | JP |
0064059 | Oct 2000 | WO |
Entry |
---|
International Search Report and Written Opinion—PCT/US2004/036599, ISA/US, Aug. 17, 2006. |
Supplementary European Search Report—EP04810264, Search Authority Munich, May 4, 2011. |
ANSI, “Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications”, ANSI/IEEE Std 802.11, 1999 Edition (2003), pp. 3 and 136. |
Number | Date | Country | |
---|---|---|---|
Parent | 10704209 | Nov 2003 | US |
Child | 13231733 | US |