WO2013137709A1

WO2013137709A1 - Frequency channel management for wireless communication device

Info

Publication number: WO2013137709A1
Application number: PCT/MY2012/000053
Authority: WO
Inventors: Reza Khoshdelniat; Pannirselvam Kanagaratnam; Gopinath Rao Sinniah
Original assignee: Mimos Berhad
Priority date: 2012-03-13
Filing date: 2012-03-13
Publication date: 2013-09-19

Abstract

The present invention discloses a method for use in managing frequency channel based on at least one wireless communication standard in a wireless communication device; whereby the main component is to create groups based on the channel frequencies of the wireless standards provided on the user's device. Based on the groups created, a table is constructed so as to enable selection of frequency channel and verifying link quality, thus avoiding frequency interference.

Description

FREQUENCY CHANNEL MANAGEMENT FOR WIRELESS COMMUNICATION DEVICE

Field of Invention

The present invention relates to the wireless communication systems, and more particularly, the invention discloses a frequency channel management method for wireless communication devices .

Background of Invention

At present, the rapid demand for more enhanced technologies in wireless network systems has resulted to the relevant contributors and innovators in the field to be on their toes and thus is constantly seeking to create value-added features or integration of features which are capable of providing a higher level of efficiency and convenience. Currently, there are several widely used standards which define the mode of operation for WLAN and WPAN, be in the ad hoc or infrastructure.

The most prominent wireless connectivity at present is WiFi (wireless fidelity) which operates based on IEEE 802.11, a dynamic protocol which allows a high speed wireless local area network (WLAN) connection for data transmission within wireless hotspots. It is known that there are several different versions of wireless systems that have advanced over time whereby the key differences include frequency band, type of wireless access, and maximum data transmission rates.

Another advancement of wireless network is WiMAX, whereby this high speed wireless wide area network (WWAN) technology takes wireless access to another level in regards to its capabilities as compared to WiFi. Typically WiFi and WiMAX deploy the IEEE 802.11 and IEEE 802.16 standards respectively, in which individually each of them provides high transmission rate in limited geographical coverage, while another offers more flexibility in addition to maintaining the technology's data rate and transmission range.

Although the existing standards provide advancements in terms of ubiquitous connectivity for users, these standards have potential frequency interference with each other. For instance, wireless standards such as IEEE 802.11, IEEE 802.16, IEEE 802.15.4 and IEEE 802.15.1 and the future wireless communication standards can have potential interference with the existing standards as well. Even between Wi-Fi, WIMAX and 802.15.4, there is frequency interference.

In the case of both Wi-Fi and 802.15.4, the frequency used is 2.4 GHz while WIMAX uses different groups of frequency ranges for their wireless communications. Typically, two groups of frequency ranges that interfere with Wi-Fi and 802.15.4 are 2.3 up to 2.4 GHz and 2.496 up to 2.69 GHz. Further, Wi-Fi has 11 channels that ranges from 2.412 GHz for channel 1 up to 2.462 GHz for channel 11. 802.15.4 which uses IEEE 802.15.4 standard has 16 channels with a range from 2.405 GHz for channel 11 up to 2.480 GHz for channel 26.

Considering the presence of interference, devices with these three wireless standards embedded, may experience tribulations, as frequency interference would lead to data loss in the event that a proper frequency management is not provided.

Although each of the above connection technologies has established its effectiveness amongst users and service providers even when deployed individually, ^' there are several emerging issues associated to the absence of frequency management between the WLAN and WPAN wireless communication standards as previously discussed. These issues include interference and signal collision, changing of frequency channels frequently this causing interruption of communication between the wireless communication device and the nodes which are communicating with said device.

Following the interference drawbacks as briefly described above, few prior art solutions are available but a great majority are focused on a specific standard thereby the effectiveness is rather restricted. US 20100091731 Al discloses a channel allocation method and apparatus for wireless communication networks, whereby the method aids to solve tribulations related to Wi-Fi and 802.15.4. Nevertheless, there is no disclosure on solving problems associated to WiMAX or using signal strength and link quality to select the most suitable channels.

Recognizing the aforementioned shortcomings, the present invention has been accomplished to significantly provide ameliorating actions with respect to the drawbacks related to signals interference between WLAN and WPAN standards.

It is therefore the primary object of the present invention to provide a method for use in channel management for wireless communication devices, particularly for devices which employs various standards such as WiMAX, Wi-Fi and 802.15.4.

In is yet an object of the present invention to provide a method for use in channel management for wireless communication devices, whereby the frequency channels used by each wireless communication standards are classified and frequency channel group are suitably created.

It is another object of the present invention to provide a method for use in channel management for wireless communication devices, whereby there is provided grouping of the frequency channels used for different wireless communication · standards so as to avoid frequency channels interfere with each other.

It is a further object of the present invention to provide a method for use in channel management for wireless communication devices, whereby the communication device is permitted to select a frequency channel for a communication standard based the frequency range given in the predetermined groupings in reference to the frequency channel used by said device, in which higher priority is on the availability and quality of the channels.

Further objects and advantages of the present invention will become apparent in the following description. Summary of Invention

There is disclosed a method for use in managing frequency channel based on at least one wireless communication standard in a wireless communication device; said method comprising the steps of: creating at least one group of channel frequency based on the wireless communication standard; creating a frequency table based on the created group of channel frequency; selecting frequency channel based on the frequency table; verifying the link quality and connectivity of the selected frequency channel; selecting an alternative channel if the link quality is below the link quality threshold. Brief Description of the Drawings

This invention will be described by way of non-limiting embodiments of the present invention, with reference to the accompanying drawings, in which:

FIG 1 shows how a wireless communication relay device establishes an interconnection among WiMAX, Wi-Fi and 802.15.4 networks.

FIG 2 shows the overall process flow of the method in accordance with a preferred embodiment of the present invention. FIG 3 shows the process flow for link quality checking and detection of new signals;

FIG 4 and FIG 5 show the general process flow for channel management in wireless relay device for WiMAX, Wi-Fi and 802.15.4;

Detailed Description of the Invention In line with the above summary, the following description of a number of specific and alternative embodiments is provided to understand the inventive features of the present invention. It shall be apparent to one skilled in the art, however that this invention may be practiced without such specific details. Some of the details may not be described at length so as not to obscure the invention.

The present invention discloses method for use in channel management, for wireless communication devices having a plurality of standards.

It should be mentioned that one of the primary components in wireless sensor networks is a gateway that is used to collect data, translate the address and route the packet to the destination. Using this application, an IP client is able to communicate with the wireless nodes directly and request data from them. There may further be provided a wireless communication relay device which is configured to receive the requests from IP client and pass the request through the 802.15.4 gateway to the wireless nodes. Suitably, said device can be used as an access point for Wi-Fi connection and a CPE for WiMAX connection.

FIG 1 shows how a wireless communication relay device establishes an interconnection among WiMAX, Wi-Fi and 802.15.4 networks. As briefly explained, there are several frequency channels for WiMAX, Wi-Fi and IEEE 802.15.4 as suitable shown in TABLE 1 below. Based on a preferred method of the present invention, a frequency channel group table is created based on the wireless communication standards used in the wireless communication device .

TABLE 1

Frequency channels used by WiMAX, Wi-Fi and 802.15.4

Channel Number Wi-Fi Center Frequency (GHz) 802.15.4 (GHz)

Wl 2.412

W2 2.417

W3 2.422

W4 2.427

W5 2.432

W6 2.437

W7 2.442

W8 2.447

W9 2.452

W10 2.457

Wll 2.462

Zll 2.405

Z12 2.41

Z13 2.415

Z14 2.42

Z15 2.425

Z16 2.43

Z17 2.435

Z18 2.44

Z19 2.445

Z20 2.45

Z21 2.455

Z22 2.46

Z23 2.465

Z24 2.47

Z25 2.475

Z26 2.48 WIMAX Frequency range (GHz)

WIMAX 1 2.3 - 2.4

WIMAX 2 2.496 - 2.69

WIMAX 3 3.3 - 3.4

WIMAX 4 3.4 - 3.8

In accordance with the preferred embodiment of the present invention, the method comprises the step of creating a frequency channel management for a wireless communication relay device between WIMAX, Wi-Fi and 802.15.4. Accordingly the frequency channels used by WIMAX, Wi-Fi and 802.15.4 are classified and frequency channel groups are created with the signal strength (RSSI) and signal to noise ratio (SNR) information of the channels.

The next step is to the grouping of frequency channel, whereby each frequency channel group includes a channel from WIMAX frequency channels, Wi-Fi channels and the frequency channels for 802.15.4 that will not interfere with each other. The grouping of frequency channel is shown in TABLE 2 below.

TABLE 2

Grouping of Frequency Channel

5 As seen in TABLE 2 above, there is provided three main groups A, B and C. Each of these groups is in reference to the WIMAX frequency range selected. It is seen that in group A there is no WIMAX connection, therefore the potentially available Wi-Fi frequency channels to be selected by the Wi-Fi access point are 10 1, 6 or 11. The Wi-Fi access point will perform a scan on channel 1, 6 and 11 and will gather the RSSI and SNR information of the channels, and then it will select a channel based on availability and quality of the channels.

15 In view of the selected channel for Wi-Fi, 1, 6 or 11, there are provided the sub-groups of 1, 2 or 3. In each sub-group the frequency channels that can be selected by the 802.15.4 gateway are defined. In accordance with the preferred embodiment of the present invention, the 802.15.4 gateway proceeds to scan the channels in the sub-group and thus gather the RSSI and SNR information of the channels, and prior to selecting a channel based on availability and quality of the channels.

As for group C the WIMAX connection is using 2.496 up to 2.69 GHz, therefore the Wi-Fi access point can select frequency channel 1, 6 or 10. As channel 11 of Wi-Fi has interference with the WIMAX frequency range, therefore channel 11 in Wi-Fi should not be selected. Subsequently, the Wi-Fi access point proceeds to perform a scan on channel 1 and 6 and gathers their RSSI and SNR information, prior to selecting a channel based on availability and quality.

In the event that one of channel 1 and 6 is not available or not free it proceeds to scan channel 10 and collect its RSSI and SNR information, and selects the channel if it is available with acceptable signal quality. Depending on which Wi-Fi channel, 1, 6 or 10 is selected, there are provided the subgroups of CI, C2 or C3. In each sub-group the frequency channels that can be selected by the 802.15.4 gateway are defined. The 802.15.4 gateway will scan the channels in the sub-group and collect their RSSI and SNR information, and then selects a channel based on availability and quality. In the event that the Wi-Fi access point communicates on channel 1, the permitted channels for 802.15.4 would be 16 up to 26 which apply to sub-groups Al and CI. If the Wi-Fi access point communicates on channel 6, the permitted channels for 802.15.4 are 11, 12, 13, 14 and 21 up to 26 which apply to subgroups A2, B2 and C2. While if the Wi-Fi access point works on channel 11, the permitted channels for 802.15.4 are 11 up to 19 which apply to sub-groups A3 and B3. When the Wi-Fi access point communicates on channel 2, the permitted channels for 802.15.4 are 17 up to 26 which apply to sub-group Bl . Then if the Wi-Fi access point communicates on channel 10, the permitted channels for 802.15.4 are 11 up to 18 which apply to sub-group C3.

Ultimately, the wireless communication device is configured to scan for signal detection starting from the wireless standard with the highest priority. The wireless communication device therefore is configured to scan all the frequency channels of the wireless standard and thus gathers the signal strength (RSSI) and signal to noise ratio (SNR) of each frequency channel. Upon completion of scanning the wireless communication device selects the channel frequency based on availability and link quality. According to the preferred embodiment of the present invention, the availability is based on non interference of the selected channel with the other possible channels used by other devices using the same wireless standard .

Following the above, after channel selection the wireless communication device initiates the process for channel selection for the next wireless standard in the channel grouping table. The available channels for each wireless standard are based on the frequency channel selected for the wireless standard with the higher priority. The wireless communication device scans the available channels in reference to the channels in the frequency channel table.

FIG 2 shows the overall process flow of the method in accordance with a preferred embodiment of the present invention.

FIG 3 shows the process flow for link quality checking and detection of new signals. Referring to FIG 3, if the link quality is below the predetermined low quality threshold, for instance below - 70dbm, the wireless communication device will in reference to channels selected for the higher and lower wireless standards in the priority list, scan the available channels that do not interfere with the selected channels for other wireless standards. The scanning will gather RSSI and SNR information of the available channels and then will select a channel based on the availability and quality. In accordance with another preferred embodiment of the present invention, in the event that a wireless relay device is used, the wireless communication relay device is configured to first scan the WIMAX frequency ranges. If it fails to detect any WIMAX signal it will work on frequency group A. If it detects WIMAX signal in the range of 2.3 up to 2.4 GHz, it will work on frequency group B. If the frequency of the signal detected is 2.496 up to 2.69 GHz, then it will work on frequency group C. In reference to the group selected, the Wi-Fi access point starts scanning to select an available Wi-Fi channel based on availability and quality. When the 802.15.4 gateway starts working, it will detect the frequency channels used for Wi-Fi. Accordingly, based on the Wi-Fi channel, it will choose the sub-group of frequency channels which will not interfere with the frequency channel used for WIMAX and Wi-Fi.

FIG 4 and FIG 5 show the general process flow for channel management in wireless relay device for WiMAX, Wi-Fi and 802.15.4.

Based on a preferred embodiment of the present invention, if at the time that the wireless communication relay device start scanning for a WIMAX signal, it fails to detect any WIMAX signal, it will be directed to select channels in reference to group A. If the WIMAX connection gets established later, the wireless communication relay device will check the Wi-Fi frequency channel.

If the WIMAX frequency is 2.3 up to 2.4 GHz and Wi-Fi channel is 1, this would lead to interference and therefore the wireless communication relay device will shift to other channels. It is configured to first scan channel 6 and 11 and their RSSI and SNR, if they are available it will shift to them. If channel 6 and 11 are not available, it proceeds to scan channel 2 and its RSSI and SNR and selects channel 2 if it is available.

Similarly, if the WIMAX frequency range is 2.496 up to 2.69 GHz and the Wi-Fi channel is 11, this is expected to have interference and thus the wireless communication relay device will shift to other channels. It proceeds to scan channel 1 and 6 and their RSSI and SNR, if they are available it will shift to them. If channel 1 and 6 are not available, it will scan channel 10 and its RSSI and SNR and will select channel 10, if it is available.

The method allows interchanging of channels based on link quality as described in earlier. For this purpose, if Wi-Fi link quality is below the low quality link threshold so that the channel should be changed, the wireless communication relay device will in reference to channels selected for Wimax and 802.15.4, proceed to scan the available channels that do not interfere with the selected channels for other wireless communications. The scanning will gather RSSI and SNR information of the available channels and then will select a channel based on the availability and quality.

In the case where 802.15.4 is used and If the 802.15.4 link quality drops so below the link quality threshold that the channel should be changed, the wireless communication relay device will in reference to channels selected for imax and Wi- Fi, will scan the available channels that do not interfere with the selected channels for other wireless communications. The scanning will gather RSSI and SNR information of the available channels and then will select a channel based on the availability and quality.

While specific embodiments have been described and illustrated, it is understood that many changes, modifications, variations and combinations thereof could be made to the present invention without departing from the scope of the invention.

Claims

A method for use in managing frequency channel based on at least one wireless communication standard in a wireless communication device; said method comprising the steps of: creating at least one group of channel frequency based on the wireless communication standard; creating a frequency table based on the created group of channel frequency; selecting frequency channel based on the frequency table; verifying the link quality and connectivity of the selected frequency channel; selecting an alternative channel if the link quality is below the link quality threshold.

2. The method as claimed in Claim 1 wherein the step of selecting frequency channel involves selecting for the wireless standard for higher priority.

3. The method as claimed in Claim 1 wherein there is a plurality of wireless standard used by said wireless communication device.

4. The method as claimed in anyone of Claim 1 to 3 wherein in the event that there is a plurality of wireless standards, the frequency channel group is created based on the priority and wireless standard with the least number of available channels as the top priority and the wireless standard with the highest number as the least priority.

5. The method as claimed in Claim 4 wherein the frequency channel group is further created on the available frequency channels for each wireless standard based on the possible selected channel for the wireless standard with higher priority.

6. The method as claimed in Claim 1, wherein the step of selecting frequency channels further comprises the steps of retrieving the selected channel for wireless standard with higher priority;

scanning the available channels in the frequency group table and gathering information based on the signal strength and signal noise ratio of available channels; selecting a channel from available group of frequency channels based on the availability and quality of channels.

7. The method as claimed in Claim 1 wherein the method further comprises the step of shifting the channel of wireless standard from the lower priority to another channel which is not interfering with the selected channels for the wireless standards of higher and lower priority.

8. The method as claimed in Claim 1 wherein the step verifying the connectivity and quality further comprises selecting available channels that do not interfere with selected frequency channels of wireless standards with higher and lower priority.

9. The method as claimed in Claim 8 wherein the verifying step further comprises the step of scanning and gathering RSSI and SNR information based on the available channels and selecting a channel based on the availability and quality of channels.

The method as claimed in Claim 1 wherein the method comprising the step of using a wireless communication relay device based on the wireless communication standards.