Abstract:
Apparatus having corresponding computer-readable media comprise: a first transceiver, wherein the first transceiver includes a receiver configured to receive a first message from a first device, wherein the first message includes a location of the first device, and a transmitter configured to transmit a second message, wherein the second message includes the location of the first device, and a request for a frequency allocation based on the location of the first device; wherein the receiver is further configured to receive a third message, wherein the third message includes the frequency allocation; and a second transceiver configured to wirelessly communicate on a frequency band indicated by the frequency allocation.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This disclosure claims the benefit of U.S. Provisional Patent Application Ser. No. 61/452,475, filed on Mar. 14, 2011, entitled “Wireless Location Assignment,” the disclosure thereof incorporated by reference herein in its entirety. 
     This disclosure is related to the following U.S. patent applications: 
     U.S. Provisional Patent Application No. 61/444,590, filed on Feb. 18, 2011, entitled “Dynamic Channel Allocation”; 
     U.S. Provisional Patent Application No. 61/451,310, filed on Mar. 10, 2011, entitled “Dynamic Channel Allocation”; 
     U.S. Provisional Patent Application Ser. No. 61/440,814, filed on Feb. 8, 2011, entitled “IEEE 802.11 af”; 
     U.S. Provisional Patent Application Ser. No. 61/443,185, filed on Feb. 15, 2011, entitled “IEEE 802.11 af”; and 
     U.S. Non-Provisional patent application Ser. No. 13/369,102, filed on Feb. 8, 2011, entitled “WLAN CHANNEL ALLOCATION”. 
     The disclosures of all of the above-referenced patent applications are hereby incorporated by reference herein in their entireties. 
    
    
     FIELD 
     The present disclosure relates generally to the field of wireless communications. More particularly, the present disclosure relates to the allocation of location-based spectrum for wireless communications. 
     BACKGROUND 
     Wireless spectrum has historically been allocated in a fixed manner. For example, a government agency may allocate a particular frequency band to a particular TV channel in a particular city while prohibiting others from using that band in that city. This fixed allocation typically persists until another allocation is made. 
     Now some wireless spectrum is being made available for wireless communications using temporary location-based allocations. That is, this spectrum will be assigned by request based on the location of the requesting wireless device. This type of spectrum is often referred to as “white space.” For example, the broadcast TV channels that became available with the switch from analog to digital TV broadcasting are often referred to as “TV white space.” TV white space offers much higher bandwidth than Wi-Fi, and is expected to support “smart appliances” and other smart devices that communicate over white space channels. For example, a user might employ white space channels to remotely monitor and control appliances such as TV sets, hot water heaters, and the like. 
       FIG. 1  illustrates a conventional white space allocation process. Referring to  FIG. 1 , a wireless device  102  determines its location using GPS signals  104 , and then sends a request  106  for white space allocation to a spectrum allocation server  108 , for example over a wide-area network (WAN)  110  such as the Internet. Request  106  includes the location of wireless device  102 . At  112 , server  108  consults a spectrum allocation database  114  to obtain an available frequency band (also referred to herein as a “channel”) based on the location of wireless device  102 . At  116  server  108  allocates the white space channel to wireless device  102 . Wireless device  102  can then communicate wirelessly over the allocated white space channel at  118 . 
     In the conventional location-based wireless spectrum allocation of  FIG. 1 , wireless device  102  must determine its location. FCC regulations for television white space mandate that Mode II devices have geolocation capabilities such as GPS receivers for this purpose. However, not all devices that could utilize white space will have such geolocation capabilities. It may be too expensive to place GPS receivers in cost-sensitive consumer devices that are not mobile. For example, a television set is stationary and would not normally be built with GPS facilities. Adding a GPS receiver to a television set is too expensive just to enable white space usage. In addition, an indoor device such as a television set may be shielded from GPS satellites, and so the television set would be unable to obtain its location. 
     Alternatively, FCC regulations require fixed devices be “professionally installed” where a licensed installer configures the location in the wireless device  102 . However, this method is very expensive, and does not allow any movement of the wireless device, even from one room to another. 
     SUMMARY 
     In general, in one aspect, an embodiment features an apparatus comprising: a first transceiver, wherein the first transceiver includes a receiver configured to receive a first message from a first device, wherein the first message includes a location of the first device, and a transmitter configured to transmit a second message, wherein the second message includes the location of the first device, and a request for a frequency allocation based on the location of the first device; wherein the receiver is further configured to receive a third message, wherein the third message includes the frequency allocation; and a second transceiver configured to wirelessly communicate on a frequency band indicated by the frequency allocation. 
     In general, in one aspect, an embodiment features computer-readable media embodying instructions executable by a computer to perform functions comprising: obtaining a location of a device from a first message received by a first transceiver of the device; causing the first transceiver to transmit a second message, wherein the second message includes an indication of the location of the device, and a request for a frequency allocation based on the location of the device; obtaining the frequency allocation from a third message received by the first transceiver; and configuring a second transceiver to wirelessly communicate on a frequency band indicated by the frequency allocation. 
     In general, in one aspect, an embodiment features computer-readable media embodying instructions executable by a computer to perform functions comprising: determining a location of the computer; causing a transceiver to wirelessly transmit a first message, wherein the first message includes an indication of the location of the computer, wherein causing the transceiver to wirelessly transmit the first message includes causing the transceiver to wirelessly transmit the first message in response to a second message received by the transceiver, wherein the second message includes a request for the location of the computer. 
     The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims. 
    
    
     
       DESCRIPTION OF DRAWINGS 
       The leading digit(s) of each reference numeral used in this specification indicates the number of the drawing in which the reference numeral first appears. 
         FIG. 1  illustrates a conventional white space allocation process according to the prior art; 
         FIG. 2  illustrates a white space allocation system according to the principles of the present disclosure; 
         FIG. 3  illustrates a digital television according to the principles of the present disclosure; 
         FIG. 4  illustrates a smartphone according to the principles of the present disclosure; 
         FIG. 5  illustrates a spectrum allocation process according to the principles of the present disclosure; and 
         FIG. 6  illustrates a white space allocation system including an access point according to the principles of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present disclosure provide assisted location-based wireless spectrum allocation for wireless devices that do not have geolocation capabilities. For clarity this spectrum is referred to herein as “white space,” and the wireless device obtaining a channel allocation in the white space and communicating over the allocated white space channel is referred to as a “white space device.” However, the disclosed embodiments apply to any wireless spectrum allocated based of the location of the wireless device. 
     As used herein, the term “server” generally refer to an electronic device or mechanism, and the terms “message,” “request,” “response,” and the like generally refer to an electronic signal representing a digital message. As used herein, the term “mechanism” refers to hardware, software, or any combination thereof. These terms are used to simplify the description that follows. The servers and mechanisms described herein can be implemented on any standard general-purpose computer, or can be implemented as specialized devices. Furthermore, while some embodiments are described with reference to a client-server paradigm, other embodiments employ other paradigms, such as peer-to-peer paradigms and the like. 
     In the disclosed embodiments, one or more “assistant” devices having geolocation capabilities provides location information to the white space device. The white space device then uses this location information to obtain a white space channel allocation. Once the white space device is allocated a white space channel, the white space device can communicate wirelessly over that channel. 
       FIG. 2  shows an embodiment where the white space device is a digital television set and the assistant device is a smartphone. Although in the described embodiments the elements of  FIG. 2  are presented in one arrangement, other embodiments may feature other arrangements. For example, the elements of  FIG. 2  can be implemented in hardware, software, or combinations thereof. 
     Referring to  FIG. 2 , digital television set (DTV)  204  has no geolocation capability, but has the capability to communicate wirelessly over white space channels with other nearby white space devices  270 . Smartphone  202  has geolocation capabilities, for example using GPS signals  104 . Smartphone  202  can communicate its location to DTV  204 , for example using a wireless local-area network (WLAN)  206 . After obtaining the location, DTV  204  can operate as an FCC Mode II device. That is, DTV  204  can obtain a white space channel allocation from a spectrum allocation server  108  and a spectrum allocation database  114  over a wide-area network (WAN)  110  according to conventional techniques such as those described above with reference to  FIG. 1 . 
       FIG. 3  shows detail of DTV  204  according to one embodiment. Although in the described embodiments the elements of  FIG. 3  are presented in one arrangement, other embodiments may feature other arrangements. For example, the elements of  FIG. 3  can be implemented in hardware, software, or combinations thereof. 
     DTV  204  includes a transceiver  306 , a motion detector  308 , an authentication circuit  310 , a cryptographic circuit  312 , and a signal strength circuit  316 . Authentication circuit  310  and cryptographic circuit  312  can be implemented as separate circuits or as one or more processors. Signal strength circuit  316  can be implemented as part of transceiver  306 . DTV  204  also includes other circuits and modules  318  such as a digital television receiver, display, speakers, remote control interface, a processor, and the like. 
     Transceiver  306  includes a network transceiver  320  to support wireless and/or wired network communications such as Internet Protocol communications and a white space transceiver  322  to support wireless communications over white space channels. Network transceiver  320  includes a network transmitter  324  and a network receiver  326 . White space transceiver  322  includes a white space transmitter  330  and a white space receiver  332 . Transceivers  320  and  322  can be implemented together, separately, or with one or more circuits in common. 
       FIG. 4  shows detail of smartphone  202  according to one embodiment. Although in the described embodiments the elements of  FIG. 4  are presented in one arrangement, other embodiments may feature other arrangements. For example, the elements of  FIG. 4  can be implemented in hardware, software, or combinations thereof. 
     Smartphone  202  includes a GPS receiver  440  that provides geolocation capabilities based on received GPS signals  438 . Smartphone  202  also includes a Wi-Fi transceiver  442  for wireless network communications. Wi-Fi transceiver  442  includes a Wi-Fi transmitter  444  and a Wi-Fi receiver  446 . Smartphone  202  also includes an accelerometer  448 , a certification circuit  450 , and a cryptographic circuit  452 . Certification circuit  450  and cryptographic circuit  452  can be implemented as separate circuits or as one or more processors. Smartphone  202  also includes other circuits and modules  454  such as a wireless phone transceiver for communications over a wireless phone network, a display, a speaker, a control interface, a processor, and the like. 
       FIG. 5  shows a process  500  for the embodiments of  FIGS. 2-4  according to one embodiment. Although in the described embodiments the elements of process  500  are presented in one arrangement, other embodiments may feature other arrangements. For example, in various embodiments, some or all of the elements of process  500  can be executed in a different order, concurrently, and the like. Also some elements of process  500  may not be performed, and may not be executed immediately after each other. 
     Process  500  generally begins with smartphone  202  obtaining its location at  502 . In the embodiment of  FIG. 2 , smartphone  202  includes a GPS receiver  440  to determine the location of smartphone  202  based on GPS signals  104  received by smartphone  202 . In order to use GPS positioning, signals  104  must not be blocked or overly attenuated. In general, this means that the position must be determined outside of any building in which DTV  204  is located. For small buildings, the difference between the locations of smartphone  202  and DTV  204  may be insignificant for the purposes of obtaining a white space channel allocation. However, in other cases, for example when DTV  204  is located deep inside a large building, the location difference may have to be accounted for. In such situations, smartphone  202  can include an accelerometer  448  or the like to measure the distance and direction between a previously-determined location of smartphone  202  and the location of DTV  204 . From this information, smartphone  202  can provide a good estimate of the location of DTV  204 . 
     Smartphone  202  then provides location information to DTV  204 . In the embodiment of  FIG. 5 , this process is initiated by a request from DTV  204 . However, other methods can be used. In some embodiments, smartphone  202  executes an application that provides the location information to DTV  204 . For example, the application can be provided by the manufacturer of DTV  204 . 
     Referring again to  FIG. 5 , at  504  smartphone  202  receives a message from DTV  204  that requests the location of DTV  204 . In the embodiment of  FIG. 2 , this request is sent by Wi-Fi from network transmitter  324  of DTV  204  to Wi-Fi receiver  446  of smartphone  202 . However, other methods of communication can be used. 
     In response to the request, smartphone  202  sends a message to DTV  204  at  510  that includes the location information. In the described embodiments, the location information includes the latitude and longitude of smartphone  202 . However, the location information can take other forms, and can include other parameters such as altitude and the like. 
     To prevent fraud in obtaining white space channel allocations, the message can be cryptographically bound. Therefore at  506  certification circuit  450  of smartphone  202  certifies the message before transmission. That is, certification circuit  450  provides proof of the identity of smartphone  202  or the user of smartphone  202 . For example, certification circuit  450  digitally signs the message. However, other certification methods can be used instead. As a further security measure, cryptographic circuit  452  of smartphone  202  encrypts the message at  508  before transmission. Various embodiments can employ symmetric key cryptography, asymmetric key cryptography, and the like. 
     The message containing the location information is sent by Wi-Fi from Wi-Fi transmitter  444  of smartphone  202  to network receiver  326  of DTV  204  at  510 . However, other methods of communication can be used. Cryptographic circuit  312  of DTV  204  decrypts the message at  512 . Authentication circuit  310  of DTV  204  authenticates the message at  514 . For example, authentication circuit  310  verifies a digital signature used to sign the message. At this point DTV  204  has the location information for smartphone  202 . 
     In some cases, DTV  204  receives responses from multiple devices at  510 . For example, if multiple smartphones  202  are within Wi-Fi range of DTV  204 , then two or more of the smartphones  202  may respond. In some embodiments, DTV  204  selects one of the smartphones  202  to obtain the most accurate position estimate. In one such embodiment, DTV  204  employs signal strength circuit  316  to select the strongest signal, which should originate from the nearest smartphone  202 . DTV  204  then takes the location information provided in the selected signal. In other embodiments, DTV  204  combines location information from two or more smartphones  202  to obtain a location estimate for DTV  204 . 
     DTV  204  then sends a request for a frequency allocation to spectrum allocation server  108  at  516 . The request includes the location of smartphone  202 . In particular, network transmitter  324  of DTV  204  sends the request to spectrum allocation server  108  over network  110 . 
     At  518  spectrum allocation server  108  selects a white space channel by indexing spectrum allocation database  114  using the location of smartphone  202 . For example, spectrum allocation database  114  can list the current frequency allocations at the location of smartphone  202 , and spectrum allocation server  108  chooses a channel that is not currently allocated for that location. 
     At  520  spectrum allocation server  108  sends a message to DTV  204 . Network receiver  326  of DTV  204  receives the message. The message indicates the white space channel allocated to DTV  204  by spectrum allocation server  108 . In some embodiments, for further security, communications between DTV  204  and spectrum allocation server  108  are certified/authenticated and/or encrypted. 
     At  522  DTV  204  configures white space transceiver  322  to use the white space channel allocated to DTV  204  by spectrum allocation server  108 . At  524  white space transceiver  322  wirelessly communicates with other white space devices  270  using wireless white space signals  118  over the white space channel allocated to DTV  204  by spectrum allocation server  108 . 
     The white space channel allocation is valid only for the location provided by DTV  204  in the spectrum allocation request. So if moved from that location, DTV  204  is no longer allowed to communicate over that white space channel. To enforce this restriction, in the embodiment of  FIG. 4 , DTV  204  includes a motion detector  308 . At  526  motion detector  308  indicates that DTV  204  has moved. At  528 , in response to the motion detection, white space transceiver  322 , including white space receiver  332  and white space transmitter  330 , ceases wirelessly communicating on the allocated white space channel. When motion detector  308  indicates that DTV  204  is once again stationary, process  500  can begin again to obtain a new white space channel allocation for DTV  204 . DTV  204  can also consider the length of time during which motion is detected. For example if someone bumped into DTV  204  or moved DTV  204  from one room to another, the motion would not last long and so should not trigger white space channel allocation process  500  again. 
     In the embodiment of  FIG. 2 , the assistant device is a smartphone  202 . In other embodiments, other sorts of devices act as assistant devices to provide location information to white space devices.  FIG. 6  shows an embodiment where the assistant device is an access point  602  in a wireless local-area network (WLAN)  606 . Although in the described embodiments the elements of  FIG. 6  are presented in one arrangement, other embodiments may feature other arrangements. For example, the elements of  FIG. 6  can be implemented in hardware, software, or combinations thereof. 
     Access point  602  can learn its location from an access point database  614  that lists locations of access points. Such access point databases  614  have been compiled and are currently in use, for example by Internet service providers. Access point  602  can then provide the location information to nearby white space devices such as DTV  204 . A computer  612  can perform this function instead, or in conjunction with access point  602 . 
     In the embodiment of  FIG. 2 , the white space device is a DTV  204 . However, it will be appreciated that the white space device can be any sort of device that is capable of white space communications. Such devices can include other electronic devices, appliances, thermostats, automobiles, and so on. 
     In the embodiment of  FIG. 2 , smartphone  202  employs GPS signals to determine its location. However, assistant devices can use any method to determine their location. For example, other satellite positioning systems are planned. Terrestrial transmitters can be used instead or in combination with such satellite systems. 
     Various embodiments of the present disclosure can be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or in combinations thereof. Embodiments of the present disclosure can be implemented in a computer program product tangibly embodied in a computer-readable storage device for execution by a programmable processor. The described processes can be performed by a programmable processor executing a program of instructions to perform functions by operating on input data and generating output. Embodiments of the present disclosure can be implemented in one or more computer programs that are executable on a programmable system including at least one programmable processor coupled to receive data and instructions from, and to transmit data and instructions to, a data storage system, at least one input device, and at least one output device. Each computer program can be implemented in a high-level procedural or object-oriented programming language, or in assembly or machine language if desired; and in any case, the language can be a compiled or interpreted language. Suitable processors include, by way of example, both general and special purpose microprocessors. Generally, processors receive instructions and data from a read-only memory and/or a random access memory. Generally, a computer includes one or more mass storage devices for storing data files. Such devices include magnetic disks, such as internal hard disks and removable disks, magneto-optical disks; optical disks, and solid-state disks. Storage devices suitable for tangibly embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, such as EPROM, EEPROM, and flash memory devices; magnetic disks such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM disks. Any of the foregoing can be supplemented by, or incorporated in, ASICs (application-specific integrated circuits). 
     A number of implementations have been described. Nevertheless, various modifications may be made without departing from the scope of the disclosure. Accordingly, other implementations are within the scope of the following claims.