Wireless network apparatus and method of channel allocation for respective radios

Wireless network device and channel configuration method of each radio unit

The present invention relates to a network device, and more particularly to a wireless network device and a channel configuration method of each radio unit.

When the number of users grows and bandwidth is shared, the demand for wireless communication transmission will become higher and higher, especially for networks in metropolitan areas.

One solution to reduce the transmission limit is to use smart antennas in local and metropolitan networks. With smart antennas, service providers can increase network traffic where needed, so that service providers can flexibly adjust according to the characteristics of each cell, and each cell can have different traffic loads. Because of this capability, smart antennas provide an effective cost-saving way to increase capacity and balance its traffic load in high-volume areas.

Figure 1 shows a traditional wireless switching system connecting multiple radio units to a higher control layer. The wireless switching system 100 includes a plurality of radio units (radio) 110(1)-110(N) and a control circuit 120, including components such as a logic link control layer (LLC). The radio units 110(1)-110(N) each include an antenna element 111, a transceiver switch 112, a power amplifier (PA) 113, a low-noise amplifier (LNA) 114, A transceiver 115, a baseband processor (BBP) 116, and a medium access control layer (MAC layer) 117. The radio unit 110 is connected to the logical connection control layer 120 through the medium access control layer 117. It can be seen in the figure that the radio units 110(1)-110(N) operate independently. The wireless switching system 100 balances the traffic load by adjusting the segment size, orientation, and effective radiation power.

However, this low-integration and non-co-location radio unit architecture cannot provide adjustment of beam and frequency channel configuration to optimize beam image and/or spectral efficiency, nor can it provide controllable and effective beam and frequency channels. isolate. Moreover, these radio units are set independently, and cannot provide array gain to increase the connection range, nor can they provide multiple bandwidths to increase the connection output.

In view of this, the purpose of the present invention is to provide a wireless network device and a channel configuration method for each radio unit to reduce the unbalanced traffic load.

According to the purpose of the present invention, a channel configuration method for each radio unit is proposed. This method first scans a plurality of sections of a phased antenna array to retrieve the basic service group identification code (Basic Service Set ID) of each beam of a specific channel. Identification, BSSID). Record the characteristic information related to each BSSID. Then, each BSSID is associated with the corresponding operating beam number and operating frequency channel number to form an initial channel configuration for each radio unit. Then, compare the initial channel configuration with a plurality of predetermined channel configuration modes, including a point-to-point (PtP) connection in the first mode, and a multipoint-to-point (MultiPoint-to-Point, PtP) connection in the second mode. MPtP) connection, a point-to-multipoint (PtMP) connection in the third mode and a multipoint-to-multipoint (MPtMP) connection in the fourth mode, and select from them The one that best matches this initial channel configurator. Then, a tracking mode or a scanning tracking mode is selectively executed. In the tracking mode, a plurality of frequency channels are assigned to each radio unit based on the selected channel configuration mode, thereby achieving the best application of the four modes. In the tracking mode with scan, multiple frequency channels are assigned to each radio unit based on the initial channel configuration, thereby achieving the best match with these scan sections. Then, monitor the traffic in these sections. Then reduce or increase one of the non-overlapping frequency channels of the radio unit to an unbalanced beam to reduce the unbalanced load.

According to another objective of the present invention, a wireless network device is provided, which includes an antenna array, a beam forming network, a multiplex switching network, a radio unit, and a control circuit. The antenna array includes a plurality of antenna elements, each having an output antenna port. The beamforming network has a plurality of input terminals, which are coupled to the output antenna ports, and has a plurality of output beam ports. The multiplex switching network has a plurality of input terminals, which are coupled to the output beam port of the beam forming network, and has a plurality of output radio ports. Radio units (radio) are used to modulate/demodulate signals. Each radio unit is selectively coupled to the output radio port of the multiplexed switching network according to a predetermined option. The control circuit is used for controlling the multiplex switching network to establish electrical communication between the antenna elements and the radio units based on a predetermined option of one of the plurality of modes. These modes include a Point-to-Point (PtP) connection in the first mode, a MultiPoint-to-Point (MPtP) connection in the second mode, and a single mode in the third mode. Point-to-MultiPoint (PtMP) connection and a fourth mode of MultiPoint-toMultiPoint (MPtMP) connection.

In order to make the above-mentioned objects, features, and advantages of the present invention more obvious and understandable, a preferred embodiment is specifically cited below, and is described in detail as follows in conjunction with the accompanying drawings:

Please refer to FIG. 2, which shows a schematic diagram of a wireless network device according to a preferred embodiment of the present invention. The wireless network device 200 includes an antenna array 210, a beamforming network 220, a multiplexer 230, a plurality of radio units 240(1)-240(N), and a control circuit 250, wherein the control circuit 250 includes a logical connection control layer And other components.

In order to reduce the interference between channels and increase the capacity of the system, the coverage area of the wireless base station is usually divided into several sub-sections. The division of the coverage area can be implemented by different types of phased antenna arrays 210, such as planar, sectored, quadrate, hexahedral, and octahedral. The architecture will be detailed later.

The antenna array 210 includes a plurality of antenna elements, and each antenna element includes an output antenna port to connect to the beam forming network 220. The number of antenna elements is 2 levels. The antenna array 210 therefore has 2^n antenna ports corresponding to the antenna elements, where n is a positive integer.

The beam forming circuit 220 has a plurality of input terminals, is coupled to the output antenna port of the antenna array 210, and has a plurality of output beam ports. These output beam ports have a one-to-one relationship with these antenna ports, so their number is 2^n. Preferably, the beam forming network 220 is a group consisting of a Rotman lens, a Butler matrix, a Wullenweber array, and a Blass matrix. Choose one.

The multiplex switching network 230 has a plurality of input terminals to be coupled to the output beam port of the beam forming network 220, and has a plurality of output radio ports. The output radio ports are respectively coupled to the radio units 240(1)-240(N).

The radio units 240(1)-240(N) are used for signal modulation/demodulation. Each radio unit 240(1)-240(N) is selectively coupled to the output radio port of the multiplex switching network 230 based on a predetermined option.

The control circuit 250 controls the multiplex switching network 230 to establish electrical communication between the antenna element of the antenna array 210 and the radio units 240(1)-240(N) based on a predetermined option based on one of a plurality of modes, according to The channel configuration of the radio unit 240 is completed. These modes include point-to-point (PtP) connection in the first mode, multipoint-to-point (MPtP) connection in the second mode, and single-point-to-many in the third mode Point (Point-to-MultiPoint, PtMP) connection and the fourth mode of MultiPoint-toMultiPoint (MPtMP) connection.

Figure 3 shows a schematic diagram of a beamforming network. In this example, the beamforming network 220 is a Butler matrix, denoted as 220(a), which uses a 90-degree hybrid coupler and a phase shifter, and is represented by a rectangle and a circle, respectively.

Each beam (labeled with a number followed by a letter, R or L) formed in the beam port can be positioned by the radio units 240(1)-240(N) through the multiplex switching network 230.

The 8x8 Butler matrix 220(a) is used to feed the antenna array 210(a) with 8 antenna elements 210(1)-210(8), and the distance between these antenna arrays is λ/2. The antenna array 220(a) is, for example, a phased array, with a coverage range of 120 degrees, and is further divided into multiple beams, each of which has a beam width of 15 degrees.

Figure 4 shows the type combination table of the phased array. This list can undoubtedly continue to be expanded. The types of phased arrays include planar, three-sided, four-part, six-part, and eight-part types. The Butler matrix 220(a) may include different numbers of ports to form a maximum 360-degree coverage area together with different types of phased arrays. The choice of the phase array and the number of ports of the Butler matrix are determined by the application system.

Figure 5 shows a schematic diagram of a multiplexed switching network. In this example, the multiplexed switching network 230 is planned as a channel configuration, and 2^n (n=1) output beam ports are connected to N (N=3) radio ports according to predetermined options. Optimize spectrum and beam pattern efficiency. The multiplex switching network 230 is coupled to the 2-port Butler matrix 220(b) in the figure, and the Butler matrix 220(b) is fed to the antenna array 210(b) of 2 antenna elements. The multiplexer 230 is further coupled to the radio unit 240, and the radio unit 240 is then connected to the control circuit 250.

The multiplex switching network 230 includes a power splitter 532, a single-pole-single-throw (SPST) switch 534, and a power combiner 536. The input ends of the 2^n power splitters 532(1) and 532(2) are coupled to the output beam ports of the 2^n Butler matrix 210(b). The output ends of the power dividers 532(1) and 532(2) are coupled to the SPST switch 534. The power divider 532 is respectively coupled to the N number of SPST switches 534, so there are (2^n)×N SPST switches 534 in total. The SPST switch 534 averagely cuts the power of each beam generated by the beam ports 1R and 1L, and outputs the power to the radio units 240(1)-240(3) through the power combiner 536.

The multiplex switching network 230 can operate in four modes of predetermined options. Figure 6A shows a point-to-point (PtP) connection multiplexed switching network operating in the first mode. The output beam port of the beamforming network 220 is marked with a number followed by a letter. The number on the right indicates the channel number. In the first mode, the output beam ports are configured to different channels. In other words, eight radio units are connected to individual beam ports and operate on different frequencies of each channel, so the space and frequency isolation can be optimized.

Figure 6B shows a multiple point-to-single point (MPtP) connection multiplexed switching network operating in the second mode. In the second mode, the beam port is connected to the channel via a multi-point-to-single-point connection. In other words, multiple radio units operate at the same frequency to optimize the efficiency of the beam pattern. In this mode of operation, the bandwidth can be increased, and the unbalanced traffic load can also be reduced.

Figure 6C shows a single point-to-multipoint (PtMP) connection multiplexed switching network operating in the third mode. In the third mode, the beam port is connected to the channel via a single point-to-multipoint connection. In other words, a radio unit operates on multiple different frequencies to optimize spectrum efficiency.

Figure 6D shows a multi-point-to-multipoint connection (MPtMP) multiplexed switching network operating in the fourth mode. In the fourth mode, the beam port is connected to the channel through a multipoint-to-multipoint connection. In other words, all beam ports can be freely operated at any frequency to optimize connection capacity.

Therefore, after pre-selecting one of the four modes, an appropriate channel configuration mechanism can be selected to optimize space and frequency isolation, beam pattern efficiency, spectrum efficiency, or connection capacity.

In order to further provide space and frequency isolation, orthogonal beams generated by hardware wiring equivalent to discrete fast Fourier transform are used in the embodiments of this case to provide better isolation between beam ports. In addition, well-shielded coaxial cables or well-isolated strip lines can provide a high isolation effect on each transmission twisted pair. Moreover, high isolation power splitters and non-reflective switches can also increase the isolation effect between different beam ports and between different radio ports.

Furthermore, channel filters, such as bandpass or band reject filters, can provide better isolation on channels without overlapping frequencies, such as channels under IEEE 802.11g specifications. 1,6,11; Channels 36,40,44,48,52,56,60,and 64 in the low/mid frequency bands of the IEEE 802.11a specification; Channels 149,153,157,161 in the high frequency bands of the IEEE 802.11a specification. Moreover, channels without overlapping frequencies with broad common protection, such as channels 1 and 11 under the IEEE 802.11g specification, can be used to provide better isolation. In addition, if these radio units are not operating at the same time, the isolation can be further strengthened.

In addition, these embodiments of the present case utilize continuous phase arrays with orthogonal space division multiplexed beams, and channels with non-overlapping frequencies of the secondary carriers of the orthogonal frequency division multiplexing frequency. Therefore, it is possible to have space and frequency Better isolation effect.

The embodiment of this case further proposes a method for configuring channels for each radio unit. FIG. 7 is a flowchart of a channel configuration method for each radio unit according to a preferred embodiment of the present invention. This method is first triggered according to a command or at boot time. The sections in the coverage area are scanned sequentially or simultaneously, as shown in step 710.

The method then executes the section scan mode to capture the Basic Service Set Identification (BSSID) of each beam of a specific channel in these sections, as shown in step 720.

Then, in step 730, based on the located feature information of each BSSID and a plurality of predetermined channel configuration modes, a configuration is formed into a track-while-sCan (TWS) mode and a tracking mode.

Then, step 740 is executed to determine whether to select the TWS mode or the tracking mode. When it is necessary to best match the scanned sites of the current section, the scanning tracking mode is selected. When the four modes of the above four pre-options are to be optimally applied, the tracking mode is selected.

If the scan tracking mode is selected, the method executes step 750 to adjust the action of balancing the traffic load to execute the scan tracking mode.

In addition, if the tracking mode is selected, the method proceeds to step 780. The operation mode is to select one of the above four modes to best match the characteristic information of the BSSID of each location, and is relatively purpose-driven and goal-oriented. That is, the first mode optimizes space and frequency isolation; the second mode optimizes beam pattern efficiency; the third mode optimizes spectrum efficiency; and the fourth mode optimizes connection capacity.

After step 750 or 780, the method proceeds to step 760. In step 760, when driven by a schedule or event, each segment is rescanned. This additional function is used to restore the lost beam and balance the load.

In step 770, the adaptive channel configuration is performed independently for all sections. In other words, all sections with multiple MAC layers execute different channel configurations in tracking mode or with scanning tracking mode. The messages from the MAC layer are processed by the logical connection control layer and/or the network. In step 775, if the adaptive channel configuration is successful, the method ends; otherwise, it returns to step 710.

Fig. 8 shows a flowchart of step 720 section scanning mode. In the segment scan mode, firstly select channels with non-overlapping frequencies sequentially from the channel with the smallest number to the channel with the largest number, as shown in step 810.

Then, in step 820, for each selected channel, the leftmost beam to the rightmost beam of each channel is sequentially split into multiple lobes.

Next, in step 830, for each positioned BSSID, the RSSI value, operating frequency channel number, and operating beam number (for example, a pattern) of the corresponding mobile station (station, STA) are recorded. Step 830 is repeated until all beams are split into multiple lobes, and all non-overlapping frequency channels are selected and scanned.

FIG. 9 is a flowchart of the steps of forming and configuring the belt scan tracking mode and the tracking mode in step 730. First, in step 910, the BSSID is related to the operating beam number and operating frequency channel number.

Next, in step 920, an initial channel configuration is formed for each radio unit in the band scan tracking mode. This configuration matches the different correlations in step 910.

Next, in step 930, the initial configuration with the scan tracking mode is compared with a plurality of predetermined channel configuration modes. These predetermined channel configuration modes include the point-to-point (PtP) connection of the first mode, and the first MultiPoint-to-Point (MPtP) connection in the second mode, Point-to-MultiPoint (PtMP) connection in the third mode and multipoint-to-multipoint in the fourth mode (MultiPoint-toMultiPoint, MPtMP) connection.

Then, in step 940, a tracking mode is selected from the predetermined channel configuration modes, and the selected mode best presents the characteristics of the initial channel configuration.

FIG. 10 shows a flowchart of executing the scan tracking mode in step 750. First, in step 1010, based on the channel configuration in the tracking and execution mode, plan the beam ports to be connected to these channels, and monitor the traffic indicators of each segment, such as throughput, packet loss, delay and/or jitter (jitter) . At the same time, the wireless network device 200 also normally performs transmission, reception or other designated activities.

Then in step 1020, online comparison of the results obtained in step 1010, if there is an unbalanced traffic load, or a certain flow indicator shows overload or low load, if yes, go to step 1030, otherwise go to step 1010.

Next, in step 1030, for each beam with unbalanced traffic, increase or decrease a channel of a non-overlapping frequency of its radio unit to reduce the unbalanced traffic load in a trial and error manner. That is, the adjacent beams corresponding to the unbalanced frequency channel are increased or decreased, and then the traffic index is checked. This step is repeated until the traffic load has reached a balance.

When step 1030 is executed, step 1040 is also executed at the same time to scan the BSSID/operation beam number/operation frequency channel number by the training beam and the unconfigured frequency channel. Therefore, in step 1045, it is determined whether the new BSSID is scanned out of the current configuration. If not, go back to step 1010 to continue monitoring the flow, if yes, go to step 1050. In step 1050, the available beam and/or frequency channel are dynamically allocated to the new BSSID.

FIG. 11 shows a flowchart of the execution tracking mode in step 780. First, in step 1110, the beam port and the channel are planned to be connected based on the channel configuration in the tracking mode. Monitor and measure the traffic indicators of each segment, such as throughput, packet loss, delay and/or jitter. At the same time, the wireless network device 200 also normally performs transmission, reception or other specified activities.

Then, in step 1120, the results obtained in step 1110 are compared online: 1) whether there is an unbalanced traffic load, and 2) whether there is a traffic indicator that indicates that the traffic is overloaded or low. If neither of these conditions exist, return to step 1110 to continue monitoring; otherwise, execute step 1130.

In step 1130, for each beam with unbalanced traffic, increase or decrease a channel of a non-overlapping frequency of its radio unit to reduce the unbalanced traffic load in a trial and error manner. That is, the adjacent beams corresponding to the unbalanced frequency channel are increased or decreased, and then the traffic index is checked. This step is repeated until the traffic load has reached a balance.

Comparing the tracking mode with scanning in Figure 10 and the tracking mode in Figure 11, it can be found that the tracking mode is less adaptive to recover the missing beam than the scanning tracking mode (steps 1040 and 1050 in Figure 10). ). However, the tracking mode is more suitable for target-oriented and purpose-driven work than the scanning tracking mode. For example, when the tracking mode is executed in the application of the wireless switch (new application in WLAN), the first mode among the predetermined options can be selected at this time; when the application is in the wireless hub (or wireless access point) The second mode can be selected when the tracking mode is executed in the application; the third mode can be selected in the application of a wireless bridge; the fourth mode can be selected in the application of a wireless mesh (mesh) network.

The wireless network device and its channel configuration method disclosed in the above embodiments of the present invention can increase beam pattern and spectrum efficiency, and can provide adaptive beam selection and frequency channel selection to effectively balance traffic load, and provide controllable and effective Space and frequency isolation. Furthermore, the arrangement of these radio units can provide an extended connection range and a variety of bandwidths to increase connection output.

In summary, although the present invention has been disclosed in the preferred embodiment as above, it is not intended to limit the present invention. Anyone who is familiar with this technique can make various changes and modifications without departing from the spirit and scope of the present invention. Retouching, therefore, the scope of protection of the present invention shall be subject to the scope of the attached patent application.

<p>100. . . Wireless switching system</p><p>110. . . Radio unit (radio)</p><p>120. . . Logic link control layer (LLC)</p><p>111. . . Antenna element</p><p>112, 241. . . Transceiver switch</p><p>113, 243. . . Power amplifier</p><p>114, 243. . . Low Noise Amplifier (LNA)</p><p>115, 244. . . transceiver</p><p>116, 245. . . Baseband processor (BBP)</p><p>117, 246. . . MAC layer</p><p>120, 250. . . Control circuit</p><p>200. . . Wireless network device</p><p>210. . . Antenna array</p><p>220. . . Beamforming network</p><p>230. . . Multiplexer</p><p>240. . . Radio unit</p><p>532. . . Power divider</p><p>534. . . SPST switch</p><p>536. . . Power combiner</p>

Figure 1 shows a traditional wireless switching system connecting multiple radio units to a higher control layer.

Figure 2 is a schematic diagram of a wireless network device according to a preferred embodiment of the present invention.

Figure 3 shows a schematic diagram of a beamforming network.

Figure 4 shows the type combination table of the phased array.

Figure 5 shows a schematic diagram of a multiplexed switching network.

Figure 6A shows a point-to-point (PtP) connection multiplexed switching network operating in the first mode.

Figure 6B shows a multiple point-to-single point (MPtP) connection multiplexed switching network operating in the second mode.

Figure 6C shows a single point-to-multipoint (PtMP) connection multiplexed switching network operating in the third mode.

Figure 6D shows a multi-point-to-multipoint connection (MPtMP) multiplexed switching network operating in the fourth mode.

FIG. 7 is a flowchart of a channel configuration method for each radio unit according to a preferred embodiment of the present invention.

Fig. 8 shows a flowchart of step 720 section scanning mode.

FIG. 9 is a flowchart of the steps of forming and configuring the belt scan tracking mode and the tracking mode in step 730.

FIG. 10 shows a flowchart of executing the scan tracking mode in step 750.

FIG. 11 shows a flowchart of the execution tracking mode in step 780.