English:
[0001] Wireless networks may operate on unlicensed bands, such as Wi-Fi. Wireless networks that use unlicensed bands may have lower costs than wireless networks that use licensed bands, such as cellular or WiMax networks. For example, deployment, maintenance and system costs of wireless networks using unlicensed bands may be lower than that of those using licensed bands.
[0002] However, wireless networks that use unlicensed bands and that are relatively large in size, may not operate effectively. For example, information may be lost and/or transmitted repeatedly in such large wireless networks due to contention and interference, as well as a lack of determinism. Manufacturers, vendors, and/or users are challenged to provide more effective methods for transmitting information over large wireless networks using unlicensed bands.
[0003] The following detailed description references the drawings, wherein:
[0004] FIG. 1 is an example block diagram of a wireless network including a plurality of wireless access points (WAP);
[0005] FIG. 2A is an example block diagram of a plurality of blocks including the WAPs of FIG. 1 ;
[0006] FIG. 2B is an example diagram of a block of FIG. 2A;
[0007] FIG. 2C is an example sequence for the block of FIG. 2B;
[0008] FIG. 2D is an example block diagram of first and last WAPs in the sequence of FIG. 2C;
[0009] FIG. 3 is an example block diagram of a computing device including instructions for transferring control of a frequency channel between WAPs according to a sequence; and
[0010] FIG. 4 is an example flowchart of a method for transferring control of a frequency channel between WAPs according to a sequence.
[0011] Specific details are given in the following description to provide a thorough understanding of embodiments. However, it will be understood by one of ordinary skill in the art that embodiments may be practiced without these specific details. For example, systems may be shown in block diagrams in order not to obscure embodiments in unnecessary detail. In other instances, well-known processes, structures and techniques may be shown without unnecessary detail in order to avoid obscuring embodiments.
[0012] Wireless networks may operate on unlicensed bands and use standards like Wi-Fi, in order to save costs, compared to operating on licensed bands. Also, an bands for licensing and/or exclusive use may not always be available in certain environments. In addition to avoiding licensing fees, wireless networks using unlicensed bands may also have lower deployment, maintenance and system costs.
[0013] Nonetheless, interference may become too great between network elements, such as wireless access points (WAP) or client devices (CD), using a same frequency channel of the unlicensed band in larger wireless networks. For example, a large wireless network, such as an oil and gas exploration system, may include thousands to millions of CDs, such as sensors, that send information to one or more WAPs over the same frequency channel. The one or more WAPs may forward the information to a central entity, such as a central command center. In this case, reliable delivery of the information may be difficult because of the interference between the CDs and/or WAPs attempting to communicate simultaneously over the same frequency channel. Further, if the CDs and/or WAPs are running on a limited power source, such as a battery, the power source may become drained more quickly, due to retransmissions of information lost to radio frequency (RF) interference. In addition, time may be wasted attempting to receive and/or transmit the information due to the RF interference.
[0014] Embodiments herein relate to transferring control of a frequency channel between wireless access points (WAP) according to a sequence where the frequency channel is part of an industrial, scientific and medical (ISM) radio band. For example, each of the WAPs sequentially transfers control of the same frequency channel according to the sequence. The transfer of control in the sequence occurs between adjacent WAPs, and the first and last WAPs in the sequence are adjacent to each other.
[0015] Embodiments may further include blocks, with each block including the plurality of WAPs. The WAPs of each block may follow the sequence, with at least two of the blocks sharing the same frequency channel, e.g. co-channel blocks. The co-channel blocks may be placed to maximize a distance therebetween to reduce RF interference. Further, the sequence may give each WAP of each block a fair chance to use the frequency channel while also reducing RF interference between both adjacent blocks and co-channel blocks. Further, power may be saved and information reception/transmission times may be reduced. Moreover, by using the ISM radio band, embodiments may be more readily deployed in different environments, such as different parts over the world, because the costs and restrictions inherent in securing a licensed band may not be present.
[0016] Referring to the drawings, FIG. 1 is an example block diagram of a wireless network 100 including a plurality of WAPs 110-1 to 110-n, where n is a natural number. The wireless network 100 may be any type of network using a transmission system including radio waves from an ISM radio band spectrum. The ISM radio band is generally used for unlicensed operations. Thus, the WAPs may, for example, be wireless LAN devices using one of the following frequency channels: 2450 MHz band (Bluetooth), 5800 MHz band (HIPERLAN), 2450 and 5800 MHz bands (IEEE 802.11/WiFi) and/or 915 and 2450 MHz bands (IEEE 802.15.4/ZigBee).
[0017] The plurality of WAPs 110-1 to 110-n share a same frequency channel that is part of the ISM radio band, such as one of the frequency channels listed above. Thus, the first WAP 110-1 uses a frequency channel usable by, for example, the second WAP 110-2. The term frequency channel may refer to a specific, pair and/or band of frequencies. For example, the frequency channel 2.450 Gigahertz (GHz) may refer to a center frequency of 2.450 GHz and a frequency range of 2.400 GHz to 2.500 GHz.
[0018] The WAPs 110-1 to 110-n may be any type of device that allows information collected from client devices (not shown) to be relayed to a remainder of the wireless network 100, such as a router, a switch, a gateway, a server, a command center and the like. The WAPs 110-1 to 110-n may include, for example, a hardware device including electronic circuitry for implementing the functionality described below, such as control logic and/or memory. In addition or as an alternative, the WAPs 110-1 to 110-n may be implemented as a series of instructions encoded on a machine-readable storage medium and executable by a processor.
[0019] Each of the plurality of WAPs 110-1 to 110-n sequentially transfers control of the same frequency channel according to a sequence. For example, the first WAP 110-1 is to transfer control of the frequency channel to the second WAP 110-2 according to the sequence. The transfer of control in the sequence occurs between adjacent WAPs 110. The first and last WAPs 110-1 and 110-n in the sequence are also adjacent to each other.
[0020] Thus, a current WAP 110 is adjacent to an other WAP 110 if the other WAP 110 is at least one of a next WAP 110 and an initial WAP 110 in the sequence. The current WAP 110 is a final WAP 110 of the sequence if the other WAP 110 is the initial WAP 110 in the sequence. For example, as shown in Fig. 1 , a frequency channel A is used by the first WAP 110-1 at time T and the frequency channel A is used by the second WAP 110-2 at time T+1. This trend of passing control of the frequency channel A between adjacent WAPs 110 continues to the last WAP 110-n at time T+n-1. At this point, the cycle may continue to repeat and the first WAP 110-1 may again use the frequency channel A at time T+n. The sequence will be explained in greater detail with respect to FIGs. 2C-2D below.
[0021] FIG. 2A is an example block diagram of a plurality of blocks 200-1 to 200- 84 including the WAPs 110 of FIG. 1. While FIG. 2A, show 84 blocks 200-1 to 200- 84, embodiment may include more or less 84 blocks 200. Each of the blocks 200-1 to 200-84 may include the plurality of WAPs 110 of FIG. 1. Each of the blocks 200- 1 to 200-84 uses one of a plurality of the frequency channels of the ISM radio band. A number shown in each block 200 may represent the frequency channel used by the WAPs 110 of that block 200.
[0022] In FIG. 2A, as there are only 12 frequency channels available and 84 blocks, the plurality of blocks 200-1 to 200-84 exceeds the plurality of frequency channels 1-12 available to the plurality of blocks 200-1 to 200-84. Thus, each of the frequency channels 1-12 is assigned to more than one of the blocks 200-1 to 200-84 and at least two of the blocks 200-1 to 200-84 use the same frequency channel. The frequency channels are assigned to maximize a distance between the at least two blocks 200 using the same frequency channel. For example, the first, seventh, thirteenth, nineteenth, forty-sixth, fifty-second and fifty-eighth blocks 200-1 , 200-7, 200-13, 200-19, 200^6, 200-52 and 200-58 have all been assigned to use the frequency channel 5 but are also spaced so as a maximize a distance therebetween.
[0023] While FIG. 2A shows one type of arrangement for the frequency channels, embodiments are not limited thereto. Further, a size of each of the blocks 200-1 to 200-84 may be based on interference tolerance between at least two of the WAPs 100 of different blocks 200 sharing the same frequency channel. In one instance, a minimum distance between two blocks 200 sharing the same frequency channel, e.g. co-channel blocks, may be determined to be 7.8 kilometers (km) and a size of each of the blocks 200 may be at least 2x3 km, in order to maintain tolerable interference power levels.
[0024] FIG. 2B is an example diagram of a block 200 of FIG. 2A and FIG. 2C is an example sequence for the block of FIG. 2B. The block 200 may represent any one of the blocks 200-1 to 200-84 shown in FIG. 2A. In this case, the block 200 is shown to include 90 WAPs 110-1 to 110-90. The number of each WAP 110-1 to 110-90 represents an order of the WAP 110-1 to 110-90 in the sequence. For example, the first WAP 110-1 may be the first WAP 110 in the sequence to control the same frequency channel while the ninetieth WAP 110-90 may be last WAP 110 in the sequence to control the same frequency channel for a given cycle. The term cycle may refer a single completion of the sequence. The number of each WAP 110 may be determined according to a desired path of the sequence. After a cycle completes, a new cycle may begin again with the first WAP 110-1. As shown in FIGs. 2B and 2C, the first and last WAPs 110-1 and 110-90 of the sequence are adjacent to each other and a transfer of the same frequency channel occurs along adjacent WAPs 110.
[0025] Each of the plurality of blocks 200-1 to 200-84 may follow the same sequence shown in FIG. 2C. Thus, a path of the sequence may be designed to minimize interference between WAPs 110 of adjacent blocks 200, such as the first and twenty-second blocks 200-1 and 200-22, as well as co-channel blocks, such as the first and seventh blocks 200-1 and 200-7. Embodiments are not limited to the sequence shown in FIGs. 2B and 2C and may include a variety of different sequences. Further, the blocks 200-1 to 200-84 may follow different sequences and/or have different timing schemes for transitioning control of the frequency channel between WAPs 110. For example, the path of the sequence may be based on, a user's, administrator's or manufacturer's preference, a timing sequence, a location of the WAPs 110, distances of the WAPs 110 from a central point, MAC addresses of the WAPs and the like.
[0026] FIG. 2D is an example block diagram of the first and last WAPs 110-1 and 110-90 in the sequence of FIG. 2C. In the embodiment of FIG. 2D, the first WAP 110-1 of the block 200 transmits a beacon or token to indicate exclusive use of the same frequency channel when the first WAP 110-1 is in control of the same frequency channel during the time period T. During the time period T, a remainder of the plurality of WAPs 110 of the block 200, such as the ninetieth WAP 110-90 may not transmit information over the same frequency channel in response to hearing the beacon of the first WAP 110-1. Similarly, when another of the WAPs 110 of the block 200 is in control of the same frequency channel and transmitting the beacon or token, a remainder of the WAPs 110 of the block 200 do not transmit information over the same frequency channel. Thus, RF interference may be reduced by limiting use of the frequency channel to a single WAP 100 of the block 200 at a time.
[0027] The WAP 110, such as the first WAP 110-1 , also transmits the beacon or token to signal to a next WAP 110, such as the second WAP 110-2, to prepare to receive control of the same frequency channel. Thus, adjacent WAPs 110 of the sequence may be physically proximate such that the beacon or token may be heard by the next WAP 110. The beacon or token may be a continuous or periodic radio signal with limited information content, such as an SSID, a channel number and security protocols such as WEP (Wired Equivalent Privacy) or WPA (Wi-Fi Protected Access).
[0028] As shown in FIG. 2D, a plurality of client devices (CD) 120-1 to 120-90 may transmit information to the plurality of WAPs 110-1 to 110-90. The CDs 120-1 to 120-n may include any type of device capable of measuring, collecting, storing and/or transmitting information to one of the WAPs 110-1 to 110-n, such as a sensor, a transmitter, and the like. For example, the block 200 may include 90 WAPs 110-1 to 110-90 and about 100 CDs 120 associated with each of the WAPs 110 110-1 to 110-90. Each WAP 110 and its associated one or more CDs 120 may be referred to as a cell (not shown). For example, the first WAP 110-1 and the first devices 120-1 may form a first cell while the ninetieth WAP 110-90 and the ninetieth devices 120-90 may form a ninetieth cell.
[0029] As noted above, the plurality of WAPs 110-1 to 110-90 share the frequency channel A, which is part of the ISM band. The frequency channel A is used, for example by the plurality of WAPs 110-1 to 110-90 to communicate with the plurality of CDs 120-1 to 120-90 and/or to each other. Each of the CDs 120-1 to 120-90 communicates with one of the WAPs 110-1 to 110-90 along the same frequency channel A when the WAP 110 is in exclusive control of the frequency channel A. For example, the first CDs 120-1 transmit information to the first WAP 110-1 using the frequency channel A during the time period T and the ninetieth CDs 120-90 transmit information to the ninetieth WAP 110-90 using the frequency channel A during the time period T+89.
[0030] Where there are a plurality of CDs 120 associated with one of the WAPs 110, the WAP 110 may poll all the associated CDs 120 for information in a sequential manner, e.g. not simultaneously, or contention based techniques, such as IEEE DCF or EDCA, in order to reduce or prevent or reduce RF interference. However, embodiments are not limited thereto and may also other methods for collecting information from the CDs 120. The first and second WAPs 110-1 and 110-90 may also forward or transmit the information to another WAP 110 and/or network entity (not shown), such as a higher level WAP, hub, router or gateway, during the respective time periods T and T+89.
[0031] The embodiment of FIG. 2D also includes a time module 150 to periodically transmit a sync command to the first WAP 110-1 and to transmit a program command to set a sequence number of at least one of the plurality of WAPs 110-1 to 110-90. The sync command may include a time to restart the sequence and/or start a new cycle. The sequence number provided by the program command to the WAP 110 may determine a position of the WAP 110 in the sequence. For example, the time module 150 may transmit the sync command at time T+90 after the last WAP 110-90 completes using the frequency channel A at time T+89. Further, the time module 150 may transmit the program command at any time T+x, where x is a natural number, but usually between cycles. Thus, the program command may be used to alter a path of the sequence, such as adding by a new WAP 110 to the sequence, removing an existing WAP 110 from the sequence and/or changing a position of a WAP 110 in the sequence, like by renumbering the first WAP 110-1 to be ninetieth in the sequence.
[0032] While FIG. 2D, shows a single time module 150 being used for the plurality of WAPs 110-1 to 110-90, embodiments may also include a plurality of time modules (not shown). For example, the plurality of time modules may have synchronized times. Each of the WAPs 110-1 and 110-90 and/or each of the blocks 200-1 to 200-84 may include one of the time modules and each of the time modules may sync a transition between the WAPs 110-1 to 110-90 in the sequences for each of the blocks 200-1 to 200-84. Further, the plurality of time modules may synchronize the sequences themselves of at least two blocks 200 using the same frequency channel, such as the first and seventh blocks 200-1 and 200-7.
[0033] The time module 150 may include, for example, a hardware device including electronic circuitry for implementing the functionality described above, such as a timer or GPS. In addition or as an alternative, the permission module 110 may be implemented as a series of instructions encoded on a machine-readable storage medium and executable by a processor.
[0034] FIG. 3 is an example block diagram of a computing device including instructions for transferring control of a frequency channel between the WAPs according to the sequence. In the embodiment of FIG. 3, the computing device 300 includes a processor 310 and a machine-readable storage medium 320. The machine-readable storage medium 320 further includes instructions 322, 324 and 326 for transferring control of a frequency channel between the WAPs (not shown) according to the sequence.
[0035] The computing device 300 may be, for example, a router, a switch, a gateway, a server, a command center or any other type of user device capable of executing the instructions 322, 324 and 326. In certain examples, the computing device 300 may included or be connected to additional components such as memories, sensors, displays, wireless access points (WAP), client devices (CD), etc.
[0036] The processor 310 may be, at least one central processing unit (CPU), at least one semiconductor-based microprocessor, at least one graphics processing unit (GPU), other hardware devices suitable for retrieval and execution of instructions stored in the machine-readable storage medium 320, or combinations thereof. The processor 310 may fetch, decode, and execute instructions 322, 324 and 326 to implement for transferring control of a frequency channel between the WAPs according to the sequence. As an alternative or in addition to retrieving and executing instructions, the processor 310 may include at least one integrated circuit (IC), other control logic, other electronic circuits, or combinations thereof that include a number of electronic components for performing the functionality of instructions 322, 324 and 326.
[0037] The machine-readable storage medium 320 may be any electronic, magnetic, optical, or other physical storage device that contains or stores executable instructions. Thus, the machine-readable storage medium 320 may be, for example, Random Access Memory (RAM), an Electrically Erasable Programmable Read-Only Memory (EEPROM), a storage drive, a Compact Disc Read Only Memory (CD-ROM), and the like. As such, the machine-readable storage medium 320 can be non-transitory. As described in detail below, machine-readable storage medium 320 may be encoded with a series of executable instructions for transferring control of a frequency channel between the WAPs according to the sequence.
[0038] Moreover, the instructions 322, 324 and 326 when executed by a processor (e.g., via one processing element or multiple processing elements of the processor) can cause the processor to perform processes, such as, the process of FIG. 4. For example, the select instructions 322 may be executed by the processor 310 to select one of a plurality of frequency channels of an ISM radio band for each of a plurality of blocks (not shown), each of the blocks including a plurality of WAPs. The provide instructions 324 may be executed by the processor 310 to provide exclusive access to the selected frequency channel of each block to a first WAP of the plurality of WAPs of each block.
[0039] The transfer instructions 326 may be executed by the processor 310 to transfer access to the frequency channel from the first WAP to a remainder of the WAPs for each block according to the sequence. The transfer of access occurs between adjacent WAPs for each of the blocks and the first WAP and a last WAP of the plurality of WAPs of the sequence for each of the blocks is adjacent. As noted above, the plurality of frequency channels is less than the plurality of blocks and the frequency channel of each block is selected to maximize a distance between the blocks having the same frequency channel.
[0040] FIG. 4 is an example flowchart of a method 400 for transferring control of a frequency channel between WAPs according to a sequence. Although execution of the method 400 is described below with reference to the wireless network 100, other suitable components for execution of the method 400 can be utilized. Additionally, the components for executing the method 400 may be spread among multiple devices. The method 400 may be implemented in the form of executable instructions stored on a machine-readable storage medium, such as storage medium 320, and/or in the form of electronic circuitry.
[0041] At block 405, the wireless network 100, such as a higher level network element (not shown), assigns a sequence to a first set and a second set of WAPs 110 accessing a frequency channel. The sequence determines an order in which each WAP 110 in each of the first and seconds sets is to receive access to the frequency channel, the frequency channel being part of an ISM radio band. Then, at block 410, the wireless network 100 transfers control of the frequency channel between the WAPs 110 in each of the first and seconds sets according to the assigned sequence. The transfer between the WAPs 110 in the first and second sets occur at a substantially same time and between adjacent WAPs 110. The transfer may be controlled in a distributed manner, such as by the individual WAPs 110 as described above with respect to the beacons, and/or a centralized manner, such as by a higher level network element transmitting control commands to the WAPs 110..
[0042] Next, at block 415, the wireless network 100 repeats the transfer of control of the frequency channel according to the sequence after all the WAPs 110 in the first and second sets have accessed the frequency channel. Only one of the WAPs 110 in each of the first and second sets controls the frequency channel at a given time. The controlling WAPs are to at least one of receive and transmit information from CDs. A distance between the first and second sets is based on tolerable interference powers of the WAPs 110. The sequence is based on maximizing distance between active WAPs in adjacent and co-channel blocks, where the active WAPs 110 are the WAPs 110 currently in control of the same frequency channel.
[0043] According to the foregoing, embodiments may provide a method and/or device for transferring control of a frequency channel between WAPs according to a sequence where the frequency channel is part of the ISM radio band. The sequence may give each WAP of each block a fair chance to use the frequency channel while also reducing RF interference between both adjacent blocks and co- channel blocks.

中文:
[0001]无线网络可以在未经许可的频带上进行操作,诸如,Wi-Fi。使用未经许可的频带的无线网络可以比使用得到许可的频带的无线网络具有较低的成本,诸如,蜂窝或WiMax网络。例如,使用未经许可的频带的无线网络的部署、维护和系统成本可以比使用得到许可的频带的那些无线网络的部署、维护和系统成本低。
[0002]然而,使用未经许可的频带以及尺寸上相对大的无线网络可能无法有效地操作。例如,由于争用和干扰以及决定的缺乏,在这种大无线网络中,信息可能丢失和/或重复地传送。制造者、厂商和/或用户为通过使用未经许可的频带的大无线网络传送信息提供更有效的方法是有挑战的。
[0003]接下来的详细描述参考了附图,其中:
[0004]图1是包括多个无线接入点(WAP)的无线网络的示例框图;
[0005]图2A是包括图1的WAP的多个块的示例框图;
[0006]图2B是图2A的块的示例图;
[0007]图2C是用于图2B的块的示例序列;
[0008]图2D是图2C的序列中的第一和最后的WAP的示例框图;
[0009]图3是包括用于依据序列转移WAP之间频率信道的控制的指令的计算设备的示例框图;以及
[0010]图4是用于依据序列转移WAP之间的频率信道的控制的方法的示例流程图。
[0011]特定的细节在接下来的描述中被给出以提供对实施例的透彻理解。然而,本领域的普通技术人员将理解的是:实施例可以在不具有这些特定细节的情形下被实施。例如,系统可以在框图中被示出以便不由于不必要的细节使实施例模糊。在其它实例中,众所周知的过程、结构和技术可以在没有不必要细节的情形下被示出以避免使实施例模糊。
[0012]相比较于在得到许可的频带上进行操作,无线网络可以在未经许可的频带上进行操作并且使用标准(像Wi-Fi)以节约成本。此外,在某些环境中,针对许可和/或排它使用的频带可能不总是可用的。除了避免许可费用之外,使用未经许可的频带的无线网络还可以具有较低的部署、维护和系统成本。
[0013]虽然如此,干扰可能在使用较大无线网络中的未经许可的频带的相同频率信道的网络元件(诸如,无线接入点(WAP)或客户端设备(CD))之间变得太大。例如,大无线网络(诸如,石油和气体勘探系统)可以包括数千至数百万的CD(诸如,传感器),其通过相同的频率信道把信息发送到一个或多个WAP。所述一个或多个WAP可以把信息转发到中央实体,诸如,中央命令中心。在这种情形下,因为试图通过相同的频率信道同时地通信的CD和/或WAP之间的干扰,信息的可靠递送可能是困难的。进一步,如果CD和/或WAP正在有限的功率源(诸如,电池组)上运行,则由于重新传送由于射频(RF)干扰而丢失的信息,所述功率源可能变得被更快地消耗。此外,由于所述RF干扰,试图接收和/或传送所述信息的时间可能被浪费。
[0014]在此的实施例涉及依据序列转移无线接入点(WAP)之间的频率信道的控制,其中所述频率信道是工业、科学和医学(ISM)无线电频带的一部分。例如,每个WAP依据所述序列顺序地转移相同频率信道的控制。序列中控制的转移发生在相邻的WAP之间,并且序列中的第一和最后的WAP是彼此相邻的。
[0015]实施例可以进一步包括块,其中每个块包括多个WAP。每个块的WAP可以遵循所述序列,所述块中的至少两个共享相同的频率信道,例如,同信道的块。同信道的块可以被放置成最大化其之间的距离,从而减少RF干扰。进一步,序列可以给每个块的每个WAP公平的机会来使用所述频率信道,而仍减少相邻块和同信道块二者之间的RF干扰。进一步,功率可以被节约并且信息接收/传送时间可以被减少。此外,通过使用ISM无线电频带,实施例可以被更容易地部署在不同的环境中(诸如,世界上的不同地方),因为使得到许可的频带安全的过程中的内在成本和限制可能不存在。
[0016]参考所述附图,图1是包括多个WAP 110-1至110-n的无线网络100的示例框图,其中n是自然数。无线网络100可以是任何类型的网络,其使用包括来自ISM无线电频带谱的无线电波的传送系统。ISM无线电频带通常被用于未经许可的操作。因此,WAP例如可以是使用接下来的频率信道中的一个的无线LAN设备:2450 MHz频带(蓝牙)、5800 MHz频带(HIPERLAN)、2450和5800 MHz频带(IEEE802.11/WiFi)、和/或915和2450 MHz频带(IEEE802.15.4/ZigBee)。
[0017]多个WAP 110-1至110-n共享作为ISM无线电频带的一部分的相同频率信道,诸如,以上所列出的频率信道中的一个。因此,第一WAP 110-1使用例如可由第二WAP 110-2使用的频率信道。术语频率信道可以指特定的频率对和/或频率带。例如,频率信道2.450吉赫兹(GHz)可以指2.450 GHz的中心频率和2.400 GHz至2.500 GHz的频率范围。
[0018]WAP 110-1至110-n可以是任何类型的设备,其允许从客户端设备(未示出)收集的信息被中继到所述无线网络100的其余部分,诸如,路由器、交换机、网关、服务器、命令中心等。WAP 110-1至110-n例如可以包括硬件设备,该硬件设备包括用于实现以下所描述的功能性的电子电路,诸如,控制逻辑和/或存储器。此外或作为可替代方案,WAP 110-1至110-n可以被实现为在机器可读存储介质上被编码并且由可由处理器执行的一系列指令。
[0019]多个WAP 110-1至110-n中的每一个依据序列顺序地转移相同频率信道的控制。例如,第一WAP 110-1依据所述序列把频率信道的控制转移到第二WAP 110-2。序列中控制的转移在相邻的WAP 110之间发生。序列中的第一WAP 110-1和最后WAP 110-n也是彼此相邻的。
[0020]因此,当前WAP 110与其它WAP 110相邻,如果其它WAP 110是序列中下一个WAP 110和初始WAP 110中的至少一个。当前WAP 110是序列的最终的WAP 110,如果其它WAP 110是序列中的初始WAP 110。例如,如图1中所示的,频率信道A由第一WAP 110-1在时间T使用,并且频率信道A由第二WAP 110-2在时间T+1使用。传递相邻WAP 110之间的频率信道A的控制的这个趋势继续到时间T+n-1处的最后的WAP 110-n。在这一点上,周期可以继续重复并且第一WAP 110-1可以再次在时间T+n使用频率信道A。所述序列将被相对于以下的图2C-2D更详细地解释。
[0021]图2A是包括图1的WAP 110的多个块200-1至200-84的示例框图。尽管图2A示出了84个块200-1至200-84,但实施例可以包括多于或少于84个块200。块200-1至200-84中的每一个可以包括图1 的多个WAP 110。块200-1至200-84中的每一个使用ISM无线电频带的多个频率信道中的一个。每个块200中所示的编号可以表示由那个块200的WAP 110使用的频率信道。
[0022]在图2A中,因为仅有12个可用频率信道和84个块,所以多个块200-1至200-84超出了对于所述多个块200-1至200-84可用的多个频率信道1-12。因此,频率信道1-12中的每个都被分配到块200-1至200-84中一个以上的块,并且块200-1至200-84中的至少两个使用相同的频率信道。所述频率信道被分配成最大化使用相同频率信道的至少两个块200之间的距离。例如,第1、第7、第13、第19、第46、第52和第58块200-1、200-7、200-13、200-19、200-46、200-52和200-58都已被分配成使用频率信道5,但也被间隔开以最大化其之间的距离。
[0023]尽管图2A示出了用于所述频率信道的一种类型的布置,但实施例不限于此。进一步,块200-1至200-84的每一个的大小可以基于共享相同频率信道的不同块200的WAP 100中的至少两个之间的干扰容差。在一个实例中,共享相同频率信道的两个块200(例如,同信道的块)之间的最小距离可以被确定为7.8千米(km),并且块200中的每一个的大小可以为至少2x3 km,以维持可容许干扰功率等级。
[0024]图2B是图2A的块200的示例图,并且图2C是用于图2B的块的示例序列。块200可以表示图2A中所示的块200-1至200-84中的任何一个。在这种情形下,块200被示出为包括90个WAP 110-1至110-90。每个WAP 110-1至110-90的编号表示序列中WAP 110-1至110-90的次序。例如,针对给定的周期,第一WAP 110-1可以是序列中的第一WAP 110以控制相同的频率信道,而第90个WAP 110-90可以是序列中的最后的WAP 110以控制相同的频率信道。术语周期可以指单个完整的序列。每个WAP 110的编号可以被依据所述序列的期望路径来确定。在周期完成之后,新的周期可以再次以第一WAP 110-1开始。如图2B和2C中所示的,序列的第一WAP 110-1和最后的WAP 110-90是彼此相邻的,并且相同频率信道的转移沿着相邻的WAP 110发生。
[0025]多个块200-1至200-84中的每一个可以遵循图2C中所示的相同序列。因此,序列的路径可以被设计成最小化相邻块200(诸如,第1和第22个块200-1和200-22)以及同信道的块(诸如,第1和第7个块200-1和200-7)的WAP 110之间的干扰。实施例不限于图2B和2C中所示的序列,并且可以包括多种不同的序列。进一步,块200-1至200-84可以遵循不同的序列和/或具有不同的计时方案以用于转换WAP 110之间的频率信道的控制。例如,序列的路径可以基于用户、管理员或制造者的偏好、计时序列、WAP 110的位置、WAP 110离中央点的距离、WAP的MAC地址等。
[0026]图2D是图2C的序列中的第一WAP 110-1和最后的WAP 110-90的示例框图。在图2D的实施例中,当第一WAP 110-1控制时间段T期间的相同频率信道时,块200的第一WAP 110-1传送信标或令牌以指示相同频率信道的排它使用。在时间段T期间,块200的多个WAP 110的其余部分(诸如,第90个WAP 110-90)响应于监听到所述第一WAP 110-1的信标可以不通过相同频率信道传送信息。相似地,当块200的WAP 110的另一个控制相同的频率信道并且传送信标或令牌时,块200的WAP 110的其余部分不通过相同的频率信道传送信息。因此,RF干扰可以通过每次把频率信道的使用限制到块200的单个WAP 100而被减少。
[0027]WAP 110(诸如,第一WAP 110-1)还传送信标或令牌以发送信号到下一个WAP 110(诸如,第二WAP 110-2),从而准备接收相同频率信道的控制。因此,所述序列的相邻WAP 110可以是物理上最近的,使得信标或令牌可以由下一个WAP 110监听到。信标或令牌可以是具有有限信息内容的连续或周期性的无线电信号(诸如,SSID)、信道编号和安全协议(诸如,WEP(有线等效加密)或WPA(Wi-Fi保护接入))。
[0028]如图2D中所示的,多个客户端设备(CD)120-1至120-90可以把信息传送到多个WAP 110-1至110-90。CD 120-1至120-n可以包括能够测量、收集、存储和/或把信息传送到WAP 110-1至110-n中的一个的任何类型的设备,诸如,传感器、传送器等。例如,块200可以包括90个WAP 110-1至110-90,以及与WAP 110 110-1至110-90中的每一个相关联的大约100个CD 120。每个WAP 110及其相关联的一个或多个CD 120可以被称为小区(cell)(未示出)。例如,第一WAP 110-1和第一设备120-1可以形成第一小区,而第90个WAP 110-90和第90个设备120-90可以形成第90个小区。
[0029]如上所述,多个WAP 110-1至110-90共享作为ISM频带的一部分的频率信道A。频率信道A例如由多个WAP 110-1至110-90使用以与多个CD 120-1至120-90和/或与彼此通信。CD 120-1至120-90中的每一个沿着相同的频率信道A与WAP 110-1至110-90中的一个通信,当WAP 110排它控制频率信道A时。例如,第一CD 120-1在时间段T期间使用频率信道A把信息传送到第一WAP 110-1,并且第90个CD 120-90在时间段T+89期间使用频率信道A把信息传送到第90个WAP 110-90。
[0030]在具有与WAP 110中的一个相关联的多个CD 120的情形下,WAP 110可以以顺序的方式(例如,非同时地)或基于争用的技术(诸如,IEEE DCF或EDCA)轮询针对信息的所有相关联的CD 120,以减少或防止或减少RF干扰。然而,实施例不限于此,并且还可以用于从CD 120收集信息的其它方法。第一和第二WAP 110-1和110-90还可以在相应的时间段T和T+89期间把信息转发或传送到另一个WAP 110和/或网络实体(未示出),诸如,较高等级的WAP、集线器、路由器或网关。
[0031]图2D的实施例还包括时间模块150以把同步命令周期性地传送到第一WAP 110-1并且传送程序命令从而设置多个WAP 110-1至110-90中的至少一个的序列编号。同步命令可以包括重新启动所述序列和/或启动新的周期的时间。由程序命令提供到WAP 110的序列编号可以确定WAP 110在所述序列中的位置。例如,时间模块150可以在最后的WAP 110-90在时间T+89使用频率信道A完成之后在时间T+90传送同步命令。进一步,时间模块150可以在任何时间T+x传送程序命令,其中x是自然数,但通常在周期之间。因此,程序命令可以被用于改变序列的路径,诸如,通过把新的WAP 110添加至序列、从所述序列移除现有的WAP 110和/或改变WAP 110在序列中的位置(像,通过在所述序列中把第一WAP 110-1重新编号至第90)。
[0032]尽管图2D示出了用于多个WAP 110-1至110-90的单个时间模块150,但实施例还可以包括多个时间模块(未示出)。例如,多个时间模块可以具有同步的时间。WAP 110-1至110-90中的每一个和/或块200-1至200-84中的每一个可以包括时间模块中的一个,并且时间模块中的每一个可以针对块200-1至200-84中的每一个在所述序列中同步WAP 110-1至110-90之间的转换。进一步,多个时间模块可以同步使用相同的频率信道的至少两个块200(诸如,第1个和第7个块200-1和200-7)的序列本身。
[0033]时间模块150例如可以包括硬件设备,所述硬件设备包括用于实现以上所描述的功能性的电子电路,诸如,计时器或GPS。此外或作为可替代的方案,权限模块110可以被实现为在机器可读存储介质上被编码并且可由处理器执行的一系列指令。
[0034]图3是包括用于依据序列转移WAP之间的频率信道的控制的指令的计算设备的示例框图。在图3的实施例中,计算设备300包括处理器310和机器可读存储介质320。所述机器可读存储介质320进一步包括用于依据序列转移WAP(未示出)之间的频率信道的控制的指令322、324和326。
[0035]计算设备300例如可以是路由器、交换机、网关、服务器、命令中心或能够执行指令322、324和326的任何其它类型的用户设备。在某些示例中,计算设备300可以被包括或连接至附加的部件,诸如,存储器、传感器、显示器、无线接入点(WAP)、客户端设备(CD)等。
[0036]处理器310可以是至少一个中央处理单元(CPU)、至少一个基于半导体的微处理器、至少一个图形处理单元(GPU)、适于检索和执行存储在机器可读存储介质320中的指令的其它硬件设备、或其组合。处理器310可以提取、解码、和执行指令322、324和326来实现用于依据所述序列转移WAP之间的频率信道的控制。作为可替代的方案或除了检索和执行指令之外,处理器310可以包括至少一个集成电路(IC)、其它控制逻辑、其它电子电路、或其组合,该组合包括多个电子部件以用于执行指令322、324和326的功能性。
[0037]机器可读存储介质320可以是包含或存储可执行指令的任何电子、磁性、光学、或其它物理存储设备。因此,机器可读存储介质320例如可以是随机存取存储器(RAM)、电可擦除可编程只读存储器(EEPROM)、存储驱动器、压缩盘只读存储器(CD-ROM)等。同样地,机器可读存储介质320可以是非临时性的。如以下详细描述的,机器可读存储介质320可以被采用一系列可执行指令来编码,以用于依据序列转移WAP之间的频率信道的控制。
[0038]此外,当指令322、324和326由处理器(例如,经由处理器的一个处理元件或多个处理元件)执行时,可以促使所述处理器执行过程,诸如,图4的过程。例如,选择指令322可以由处理器310执行,以针对多个块(未示出)中的每一个选择ISM无线电频带的多个频率信道中的一个,每个块包括多个WAP。提供指令324可以由处理器310执行以向每个块的多个WAP中的第一WAP提供对每个块的所选择的频率信道的排它接入。
[0039]转移指令326可以由处理器310执行以依据序列针对每个块把对频率信道的接入从第一WAP转移到WAP的其余部分。针对每个块,接入的转移发生在相邻WAP之间,并且针对每个块,序列的多个WAP的第一WAP和最后的WAP是相邻的。如上所述,所述多个频率信道少于所述多个块,并且每个块的频率信道被选择成最大化具有相同频率信道的块之间的距离。
[0040]图4是用于依据序列转移WAP之间的频率信道的控制的方法400的流程图。尽管方法400的执行下面被参考无线网络100描述,但用于方法400的执行的其它适合部件可以被使用。附加地,用于执行方法400的部件可以在多个设备之间被散布。方法400可以以存储在机器可读存储介质(诸如,存储介质320)上的可执行指令的形式和/或以电子电路的形式被实现。
[0041]在块405,无线网络100(诸如,较高等级的网络元件(未示出))把序列分配到接入频率信道的第一组和第二组WAP 110。所述序列确定了所述第一和第二组的每一个中的每个WAP 110将以其接收对频率信道的接入的次序,所述频率信道是ISM无线电频带的一部分。然后,在块410,无线网络100依据所分配的序列在所述第一和第二组的每一个中的WAP 110之间转移频率信道的控制。所述第一和第二组中的WAP 110之间的转移在基本上相同的时间并且在相邻的WAP 110之间发生。所述转移可以以分布式的方式(诸如,由以上相对于信标描述的单独WAP 110)和/或以集中式的方式(诸如,由把控制命令传送到WAP 110的较高等级的网络元件)加以控制。
[0042]接下来,在块415,在所述第一和第二组中的所有WAP 110已接入所述频率信道之后,无线网络100重复依据序列转移频率信道的控制。仅所述第一和第二组的每一个中的WAP 110之一在给定的时间控制所述频率信道。控制WAP是接收和传送来自CD的信息中的至少一个。第一和第二组之间的距离基于WAP 110的可容许干扰功率。所述序列基于相邻和同信道块中的活跃WAP之间的最大化的距离,其中活跃WAP 110是当前控制相同频率信道的WAP 110。
[0043]依据前面所述,实施例可以提供用于依据序列转移WAP之间的频率信道的控制的方法和/或设备,其中所述频率信道是ISM无线电频带的一部分。所述序列可以给每个块的每个WAP公平的机会来使用所述频率信道,而仍减少相邻块和同信道块二者之间的RF干扰。