TWI416969B - Wireless terminal and method for roaming decision - Google Patents

Abstract

The present invention provides a wireless terminal. The wireless terminal includes: monitoring module monitors whether the wireless terminal receives the signal from the second AP; decoding module decodes the signal from the first AP and the second AP, and gets the correct probability of every bit from the signal; computing module computes the correct probability mean and variance of all bits from the first AP and the correct probability mean of all bits from the second AP; comparing module compares whether the difference of mean between the first AP and the second AP is greater than the product of the variance and the roaming weight; switching module makes the wireless terminal access the network by the second AP when the difference is greater than the product.

Description

Wireless terminal and method for determining to initiate roaming

The present invention relates to a wireless terminal and a method thereof for determining to initiate roaming.

The wireless terminal accesses the wireless network through an AP (Access Point) to communicate with the wireless network. In the following cases, the wireless terminal switches between APs: (1) the wireless terminal leaves the area covered by the currently connected AP frequency band; (2) the currently used AP frequency band is seriously interfered; 3) The currently connected AP stops working; (4) The currently used AP band is very busy, and there is an optional lightly loaded AP band.

Currently, a wireless terminal usually determines whether to initiate roaming based on CCQL (Combined Communications-Quality & Load, combined with communication quality and load), and switches the connection between APs. The CCQL values are calculated based on the following parameters: (1) the average signal level displayed by the received beacon and the average noise level of the data received by the current channel; (2) the load; and (3) the signal-to-noise ratio of the detected response. This method of deciding whether or not to initiate roaming simply relies on signal strength, and in the case of severe signal interference, it is not possible to make a correct decision based on the actual wireless network signal condition. After the roaming is initiated, the quality of the communication and the performance of the network cannot be guaranteed.

In view of the above, it is necessary to provide a wireless terminal that can rely on actual communication. The status determines whether or not to initiate roaming.

It is also necessary to provide a method for the wireless terminal to decide to initiate roaming, and can decide whether to initiate roaming depending on the actual communication status.

A wireless terminal accesses a wireless network by using a first AP, where the wireless terminal includes: a listening module, configured to listen to whether the wireless terminal receives a signal sent by a second AP other than the signal sent by the first AP; a decoding module, configured to decode signals from the first AP and the second AP separately when the signal from the second AP is detected, to obtain a correct probability of each bit of the received signal; Calculating the average and variance of the correct probability of all bits of the signal from the first AP for a predetermined period of time, and the average of the correct probability of all bits of the signal from the second AP; the comparison module is used to compare Whether the difference between the average value of the correct probability of all the bits of the signal of the second AP and the average value of the correct probability of all the bits of the signal from the first AP is greater than the product of the variance and the roaming weight; the switching module is used for the average value When the difference is greater than the product, the wireless terminal is switched to access the wireless network through the first AP to access the wireless network through the second AP.

A method for a wireless terminal to initiate roaming, the wireless terminal accessing a wireless network by using a first AP, the method comprising: a decoding step: when detecting that the wireless terminal receives a signal sent by the first AP from the second AP The signals from the first AP and the second AP are respectively decoded to obtain the correct probability of each bit of the received signal; and the calculating step: calculating all the signals from the first AP within a preset time period The average and variance of the correct probability of the bit, and the average of the correct probability of all bits of the signal from the second AP; comparison step: comparing the average of all bit correct probabilities of the signal from the second AP with the first AP All bits of the signal Whether the difference between the average values of the correct chances is greater than the product of the variance and the roaming weight. If the difference between the average values is greater than the product, the process proceeds to a switching step. If the difference between the average values is not greater than the product, the maintenance step is entered; Switching the wireless terminal to the wireless terminal through the first AP to access the wireless network to access the wireless network through the second AP; maintaining the step of: maintaining the wireless terminal accessing the wireless network through the first AP.

Compared with the prior art, the wireless terminal and the method for determining to initiate roaming may depend on the actual communication condition instead of the simple signal strength to decide whether to initiate roaming, even in the case that the communication is seriously interfered, Guarantee the quality of communication and network performance after initiating roaming.

1‧‧‧Wireless terminal

2‧‧‧Wireless network

3‧‧‧First AP

4‧‧‧second AP

10‧‧‧ processor

11‧‧‧ memory

12‧‧‧Setup module

13‧‧‧Listing module

14‧‧‧Decoding module

15‧‧‧Computation Module

16‧‧‧Comparative Module

175‧‧‧Switching module

1 is a diagram showing an operating environment of a wireless terminal in a preferred embodiment of the present invention.

2 is a hardware structural diagram of a wireless terminal of the present invention.

3 is a flow chart of a preferred embodiment of a method for determining a method for initiating roaming by a wireless terminal of the present invention.

Referring to FIG. 1, a diagram of an operating environment of a wireless terminal in a preferred embodiment of the present invention.

In this embodiment, the wireless terminal 1 currently accesses the wireless network 2 through the first AP 3, and the A area is an area covered by the frequency band of the first AP 3. The second AP 4 is adjacent to the first AP 3, but the wireless terminal 1 does not currently access the wireless network 2 through the second AP 4, and the B area is the area covered by the frequency band of the second AP 4. When the wireless terminal 1 receives the signal transmitted by the second AP 4 in addition to the signal transmitted by the first AP 3, it needs to decide whether to initiate roaming. The initiating roaming means that the wireless terminal 1 will access the first AP 3 without The line network is switched to access the wireless network through the second AP 4.

Referring to FIG. 2, it is a hardware structure diagram of the wireless terminal of the present invention. The wireless terminal 1 includes a processor 10, a memory 11, a setting module 12, a listening module 13, a decoding module 14, a computing module 15, a comparison module 16, and a switching module 17. The processor 10 is configured to control each module to decide whether to initiate roaming, and to switch the connection with the AP to implement roaming.

The setting module 12 is configured to set a preset time and store it in the memory 11. For example, the preset time can be 5 seconds.

The listening module 13 is configured to listen to the signal sent by the first AP 3 received by the wireless terminal 1 and listen to the received signal sent by the second AP 4.

When the listening module 13 detects that the wireless terminal 1 receives the signal from the first AP 3 and receives the signal from the second AP 4, the decoding module 14 pairs the first AP 3 and the second AP. The signals of 4 are respectively decoded to obtain the correct probability of each bit of the received signal, and are stored in the memory 11. The bit is the bit, which is the smallest unit of the binary digit, and each 0 or 1 is a bit. The correct probability of each bit is the ratio of the correct number of bits to the total number of received bits in the received signal. If the current wireless terminal 1 receives a total of 10 bits of signals, 8 of which are correct, the correct probability of each bit is 0.8.

In the preferred embodiment, the decoded signal can use the BCJR algorithm. The BCJR algorithm is a codec error correction algorithm used to calculate the maximum likelihood probability, which can decode the received signal and calculate the correct probability of each bit of the signal.

The calculation module 15 is used for all signals from the first AP 3 in the memory 11 The correct probability of the bit calculates the average of the correct probability of all bits of the signal received by the first AP 3 within the preset time, and the correct probability of all bits according to the signal from the second AP 4 in the memory 11. The average value of the correct probability of all the bits of the second AP 4 received in the preset time is calculated, and the two average values are stored in the memory 11. The preset time refers to a time period formed by the listening module 13 detecting the time from the second AP 4 signal and pushing back a preset time.

For example, if the preset time is set to 5 seconds, the calculation module 15 calculates an average value of the correct probability of all the bits of the signal from the first AP 3 within the preset time, that is, the calculation is heard from the listening module 13 The time from the second AP 4 signal begins, pushing back the average of the correct probability of all bits of the signal from the first AP 3 over a period of 5 seconds. If the time from the second AP 4 signal is detected is 9:10:5, the preset time refers to the time between 9:10:5 and 9:10:10.

The calculation module 15 is further configured to calculate, according to the average value of all bit correct probabilities of the signals from the first AP 3 calculated above, a variance of all the correct probabilities of signals from the first AP 3 in a preset time, and It is stored in the memory 11. This variance is used to reflect the load of the first AP 3 band.

The comparison module 16 is configured to compare whether the difference between the average value of all bit correct probabilities of the signals from the second AP 4 and the average value of all bit correct probabilities of the signals from the first AP 3 is greater than the variance and a roaming weight The product of. It is experimentally found that in the case where the wireless terminal 1 currently accesses the wireless network 2 through the first AP 3 and listens to the second AP 4 transmitting a signal, the roaming weight is a constant 0.25. The product of the above variance and the roaming weight represents a roaming threshold.

Assume that the correct probability of each bit of the received first AP 3 signal is X1, and the average value of all X1s from the first AP 3 is E(X1) within a preset time, from the first AP within a preset time. The variance of all X1s of 3 is D(X1), and the correct probability of each bit of the received second AP 4 signal is X2, and the average value of all X2s received from the second AP 4 is E in a preset time ( X2). The comparison module 16 is then used to compare whether [E(X2)-E(X1)] is greater than 0.25 x D(X1).

The switching module 17 is configured to switch the wireless terminal 1 to the wireless terminal 1 through the first AP 3 access wireless network when the difference between the average values is greater than the product of the variance and the roaming weight, and access the wireless network through the second AP 4 Road 2.

Referring to FIG. 3, it is a flowchart of a preferred embodiment of a method for determining a method for initiating roaming by a wireless terminal of the present invention. It should be noted that, currently, the wireless terminal 1 accesses the wireless network 2 through the first AP 3, and the setting module 12 presets a preset time, for example, the preset time is 5 seconds.

Step S100, when the listening module 13 detects that the wireless terminal 1 receives the signal from the first AP 3 and receives the signal from the second AP 4, the decoding module 14 is from the first The signals of one AP 3 and the second AP 4 are respectively decoded to obtain the correct probability of each bit of the received signal, and are stored in the memory 11.

Step S102, the calculation module 15 calculates an average value of the correct probability of all the bits of the signal from the first AP 3 in the preset time, and an average value of the correct probability of all the bits of the signal from the second AP 4, And stored in the memory 11.

In step S104, the calculation module 15 calculates the variance of all the correct probabilities of the signals from the first AP 3 in the preset time, and stores them in the memory 11.

Step S106, the comparison module 16 compares whether the difference between the average value of all bit correct probabilities of the signals from the second AP 4 and the average value of all bit correct probabilities of the signals from the first AP 3 is greater than the variance and The product of the roaming weights. If the difference between the average values is greater than the product, the process proceeds to step S108, and if the difference between the average values is not greater than the product, the process proceeds to step S110.

In step S108, the switching module 17 switches the wireless terminal 1 to the wireless network 2 through the first AP 3 to access the wireless network 2.

In step S110, the wireless terminal 1 continues to access the wireless network 2 through the first AP 3.

In summary, the present invention complies with the requirements of the invention patent and submits a patent application according to law. The above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiments, and equivalent modifications or variations made by those skilled in the art in light of the spirit of the present invention are It should be covered by the following patent application.

1‧‧‧TOF camera unit

10‧‧‧Photographing

11‧‧‧Activity unit

12‧‧‧ Processor

13‧‧‧ memory

101‧‧‧Create module

102‧‧‧ Shooting module

103‧‧‧Detection module

104‧‧‧Analysis module

105‧‧‧Control Module

Claims (5)

A wireless terminal, the wireless terminal accessing a wireless network by using a first AP, the wireless terminal comprising: a listening module, configured to listen to whether the wireless terminal receives a second AP sent in addition to the signal sent by the first AP a signal; a decoding module, configured to decode signals from the first AP and the second AP separately when detecting a signal from the second AP, to obtain a correct probability of each bit of the received signal; a group for calculating an average value and a variance of all bit correct probabilities of signals from the first AP for a predetermined period of time, and an average of all bit correct probabilities of signals from the second AP; a comparison module for Comparing whether the difference between the average of all bit correct probabilities of the signals from the second AP and the average of all bit correct probabilities of the signals from the first AP is greater than the product of the variance and the roaming weight; and the switching module is used when When the difference between the average values is greater than the product, the wireless terminal is switched to access the wireless network through the first AP to access the wireless network through the second AP. The wireless terminal of claim 1, wherein the wireless terminal further comprises: a setting module, configured to set the preset time. A method for a wireless terminal to initiate roaming, the wireless terminal accessing a wireless network by using a first AP, the method comprising: a decoding step: when detecting that the wireless terminal receives a signal sent by the first AP from the second AP Signals from the first AP and the second AP are respectively solved Code, obtaining the correct probability of each bit of the received signal; calculating step: calculating the average and variance of the correct probability of all bits of the signal from the first AP for a predetermined period of time, and the signal from the second AP The average of the correct probabilities of all the bits; the comparison step: comparing whether the difference between the average of the correct probability of all bits of the signal from the second AP and the average of all the correct probabilities of the signals from the first AP is greater than the above variance The product of the roaming weight, if the difference between the average values is greater than the product, enter a handover step, if the difference between the average values is not greater than the product, then enter a holding step; the switching step: accessing the wireless terminal through the first AP to the wireless network The circuit is switched to the wireless terminal to access the wireless network through the second AP; the maintaining step: keeping the wireless terminal accessing the wireless network through the first AP. The method for initiating roaming is determined by the wireless terminal according to claim 3, the method further comprising: setting step: presetting a preset time before the decoding step. The method for initiating roaming is determined by the wireless terminal according to claim 3, the method further comprising: a listening step of: listening to the wireless terminal to receive a second signal other than the signal sent by the first AP, before the decoding step The signal sent by the AP.