Patent Application
20100315996
This application claims the benefit of priority based on Taiwan Patent Application No. 098119519 filed on Jun. 11, 2009.
Not applicable.
1. Field of the Invention
The present invention relates to a host apparatus, a transmission method and a tangible machine-readable medium storing a program of the transmission method for use in the host apparatus, and more particularly, relates to a host apparatus, a transmission method and a tangible machine-readable medium storing a program of the transmission method for use in the host apparatus capable of predicting a moving path of a mobile node.
2. Descriptions of the Related Art
With continuous advancement in science and technology, people are imposing ever higher requirements on communications. Nowadays, more and more importance is being attached to convenience of communications in addition to requirements on quality of communications. Wireless communications are advantageous in that they provide higher mobility by obviating the need of physical communication network wiring. Therefore, wireless-communication-enabled products such as mobile phones, notebook computers and the like are more and more popular in recent years and have become the mainstream products in the consumer electronics market.
Typically, a wireless-communication-enabled product is carried by a user to move about, so it may be considered as a mobile node. Due to the mobility of mobile node, it is impossible to establish a fixed burst routing path in the wireless network. To maintain a certain level of wireless communication quality, access points are typically deployed widely by communication service providers to transmit signals (which may be viewed as burst transmission) to mobile nodes through broadcasting. This can avoid mobile nodes from failing to continuously receive the service provided by the service provider when moving out of signal coverage of an access point.
However, this transmission method that transmits bursts through broadcasting has the following disadvantages:
In summary, efforts still have to be made in the art to provide mobile nodes in the wireless network with good wireless communication quality without consuming massive wireless network resources and register space resources of access points.
One objective of the present invention is to provide a solution for wireless communication. According to this solution, access points in possible moving paths of a mobile node are known from a statistics table, and then signal transmissions (i.e., burst transmissions) are carried out through multicast via the access points in the possible moving paths. This solution may not only provide mobile nodes in the wireless network with good wireless communication quality, but also reduce unnecessary consumption of wireless network resources and usage of register space resources of access points.
To this end, the present invention provides a host apparatus for use in a wireless network comprising a first access point, a second access point and a mobile node. The host apparatus is wirelessly connected to the first access point and the second access point. The first access point has a first signal coverage and transmits positioning information relating to the mobile node to the host apparatus, the second access point has a second signal coverage, and the mobile node is within the first signal coverage. The host apparatus comprises a storage module, a transceiver, a determination module and an update module.
The storage module is configured to store a statistics table relating to the mobile node. The transceiver is configured to receive the positioning information. The update module is configured to update the statistics table of the storage module according to the received positioning information. The determination module is configured to confirm that the mobile node is currently within the first signal coverage according to the received positioning information to generate a confirmation result, and determine that the mobile node is moving toward the second signal coverage according to the updated statistics table and the confirmation result, so as to add the second mobile node to a transmission list. The transceiver is further configured to transmit a burst to the second access point in a multicast way according to the transmission list so that the mobile node may receive the burst via the second access point after entering the second signal coverage.
To this end, the present invention further provides a transmission method for use in a host apparatus. The host apparatus is adapted to be used in a wireless network comprising a first access point, a second access point and a mobile node. The host apparatus is wirelessly connected to the first access point and the second access point, and stores a statistics table relating to the mobile node. The first access point has a first signal coverage and transmits positioning information relating to the mobile node to the host apparatus, the second access point has a second signal coverage, and the mobile node is within the first signal coverage.
The transmission method comprises the following steps of: (a) receiving the positioning information; (b) updating the statistics table according to the received positioning information; (c) confirming that the mobile node is within the first signal coverage according to the received positioning information to generate a confirmation result; (d) determining that the mobile node is moving toward the second signal coverage according to the updated statistics table and the confirmation result to add the second access point to a transmission list; and (e) transmitting a burst to the second access point in a multicast way according to the transmission list so that the mobile mode may receive the burst via the second access point after entering the second signal coverage.
To this end, the present invention provides a tangible machine-readable medium storing a program of a transmission method for use in a host apparatus. The host apparatus is adapted to be used in a wireless network and comprises a storage module, a transceiver, an update module and a determination module. The wireless network comprises a first access point, a second access point and a mobile node. The host apparatus is wirelessly connected to the first access point and the second access point. The storage module stores a statistic table relating to the mobile node, the first access point has a first signal coverage and transmits positioning information relating to the mobile node to the host apparatus, the second access point has a second signal coverage, and the mobile node is within the first signal coverage.
The program of the transmission method is loaded into the host apparatus via a computer to execute: a code A enabling the transceiver to receive the positioning information; a code B enabling the update module to update the statistic table according to the received positioning information; a code C enabling the determination module to confirm that the mobile node is currently within the first signal coverage according to the positioning information to generate a confirmation result; a code D enabling the determination module to determine the mobile node is moving toward the second signal coverage according to the updated statistic table and the confirmation result to add the second access point to the transmission list; and a code E enabling the transceiver to transmit a burst to the second access point in a broadcast way according to the transmission list so that the mobile node may receive the burst via the second access point after entering the second signal coverage.
The detailed technology and preferred embodiments implemented for the subject invention are described in the following paragraphs accompanying the appended drawings for people skilled in this field to well appreciate the features of the claimed invention.
In the following description, this invention will be explained with reference to embodiments thereof. However, these embodiments are not intended to limit this invention to any specific environment, applications or particular implementations described in these embodiments. Therefore, description of these embodiments is only for purpose of illustration rather than to limit this invention. It should be appreciated that, in the following embodiments and the attached drawings, elements unrelated to this invention are omitted from depiction; and dimensional relationships among individual elements in the attached drawings are illustrated only for ease of understanding, but not to limit the actual scale.
A first embodiment of the present invention is shown in
In the wireless network 1, the host apparatus 2 is wirelessly connected to the access points A, B, C and D, and each of the access points A, B, C and D has a signal coverage. For example, the access point A has a first signal coverage, and the access point B has a second signal coverage. The mobile node 19 is currently positioned within the first signal coverage of the access point A.
Hereinafter, how the host apparatus 2 determines possible moving paths of the mobile node 19, and transmits a burst to the mobile node 19 via access points in the possible moving paths will be described. Referring to
The determination module 27 is configured to confirm that the mobile node 19 is currently within the first signal coverage of the access point A according to the received positioning information 30 to generate a confirmation result, and determine that the mobile node 19 is moving toward the second signal coverage according to the updated statistics table 210 and the confirmation result, so as to add the access point B to a transmission list 270. The transceiver 23 is further configured to transmit a burst 230 to the access point B through multicast according to the transmission list 270 so that the mobile node 19 may receive the burst 230 via the access point B after entering the second signal coverage.
In other words, when the mobile node 19 is moving from the first signal coverage toward the second signal coverage, the mobile node 19 may be viewed as moving from the access point A toward the access point B, so the access point B is determined by the determination module 27 to be an access point in a possible moving path of the mobile node 19 and is added to the transmission list 270 so that the transceiver 23 of the host apparatus 2 can transmit data to the mobile node 19 via the access point B.
It should be noted that, although this embodiment is described only by adding the access point B to the transmission list 270, other access points (e.g., the access points C and/or D) may also exist in the possible moving paths of the mobile node 19. In this case, by following the same way as that used to add the access point B to the transmission list 270, the determination module 27 may add the other access points in the possible moving paths of the mobile node 19 to the transmission list 270 so that the transceiver 23 can transmit the burst 230 to the mobile station 19 again through multicast via all the access points in the transmission list 270.
Additionally, to ensure receipt of the burst 230 by the mobile node 19, the determination module 27 is further configured to, after the transceiver 23 has transmitted the burst 230 through multicast according to the transmission list 270, determine whether the transceiver 23 has received a receipt acknowledgement signal 32 transmitted by the mobile node 19 during a specific time period and generate a determination result.
If the determination result indicates that the transceiver 23 has received the receipt acknowledgement signal 32 during the specific time period, the determination module 27 determines that the burst 230 has certainly been received by the mobile node 19 according to the receipt acknowledgement signal 32. Otherwise, if the determination result indicates that the transceiver 23 did not receive the receipt acknowledgement signal 32 during the specific time period, the determination module 27 generates an enable signal 272 for transmission to the transceiver 23 according to the determination result, and the transceiver 23 transmits the burst 32 again through broadcast according to the enable signal 272 so that the mobile node 19 can receive the burst 32 via one of the access point A and the access point B.
Next, how the statistics table stored in the storage module 21 is updated and how the determination module 27 determines that the access point B is in the possible moving paths of the mobile node 19 will be illustrated more clearly. In more detail, the statistics table of the storage module 21 at least contains data amount information, count information corresponding to the mobile node 19, probability information corresponding to the mobile node 19, broadcast overhead information, and communication path information corresponding to the second access point. Firstly, functions of the count information and the probability information will be described. Referring to Table 1, how the count information and the probability information, both corresponding to the mobile node 19, are expressed in the statistics table of the storage module 21 is presented.
In Table 1, A→B represents that the mobile node 19 is currently at the access point B and its previous position is the access point A. The letters A, B, C and D indicated in the top row represent the next position of the mobile node 19. For example, the field A→B in combination with the field C represent that the mobile node 19 moves from the access point A to the access point B (i.e., the mobile node 19 is currently at the access point B) and the next position thereof will be the access point C. The numeral “40” indicated at an intersection of the field A→B and the field C is the count information relating to the field A→B, which counts the times that the mobile node 19 moves from the access point A to the access point B and then to the access point C. The percentage “40%” indicated at an intersection of the field A→B and the field C is the probability information of the mobile node 19 moving from the access point A to the access point B and then to the access point C, which is calculated from 40/(20+30+40+10). Meanings of other fields in Table 1 can be interpreted similarly and, thus, will not be further described herein.
Additionally, the data amount information is configured to record an upper limit of the amount of data that can be stored in each row of Table 1. In this embodiment, each row of Table 1 can store 100 pieces of data at most. Taking the row corresponding to A→B as an example, the number of data pieces stored therein is a sum of the numerals indicated in the count fields, i.e., 20+30+40+10=100 (which is the upper limit of the amount of data that can be stored in this row). The broadcast overhead information is configured to record the resource overhead necessary for the wireless network 1 to broadcast a burst. The communication path information is configured to record depth of each of communication paths in the wireless network 1.
Referring back to
In more detail, upon receiving the positioning information 30, the update module 25 is aware that a piece of data relating to the mobile node 19 needs to be stored into Table 1. As can be known from the aforesaid assumption that the mobile node 19 currently stays at the access point A all along and the next position will be the access point B, the previous position of the mobile node 19 is the access point A, the current position thereof is also the access point A and the next position will be the access point B. Hence, the count stored at the intersection of the row A→A and the column B of Table 1 shall be updated from 70 into 71, thereby obtaining the updated count information.
However, the number of data pieces in the row A→A now amounts to 101, which exceeds the upper limit of data pieces that can be stored in each row, so the update module 25 makes an approximate calculation to subtract the previous probability from the count 71 stored at the intersection of the row A→A and the column B, i.e., 71−0.7=70.3, and takes the value 70.3 as the updated probability. Other probabilities are also updated in the same way and thus will not be further described herein. The updated probability information and the updated count information are as shown in
Next, how the determination module 27 chooses the access point B and adds it to the transmission list 270 will be described. Referring to
The calculation unit 275 is configured to generate a calculation result 276 relating to the access point B according to the updated probability information 216, the broadcast overhead information 212 and the communication path information 214. The confirmation unit 271 is further configured to determine that the mobile node 19 is moving toward the second signal coverage according to the calculation result 276, so as to add the access point B to the transmission list 270.
In particular, assuming that the wireless network 1 needs to broadcast via four access points and the communication path relating to the access point B has a depth of one access point, then the broadcast overhead information 212 is equal to 4 and the communication path information 214 is equal to 1. Furthermore, according to Table 2 and the aforesaid assumption that the previous position of the mobile node 19 is at the access point A, the current position is also at the access point A and the next position will be the access point B, the updated probability information 216 is 70.3%. As the broadcast overhead information 212 divided by the communication path information 214 is greater than the updated probability information 216, the confirmation unit 271 determines that the access point B shall be added to the transmission list 270 according to the calculation result 276.
In particular, the transmission method of the second embodiment may be implemented by a computer program product, when being loaded into the host apparatus 2 via a computer and a plurality of codes thereof are executed, can accomplish the transmission method of the second embodiment. This computer program product may be stored in a tangible machine-readable medium, such as a read only memory (ROM), a flash memory, a floppy disk, a hard disk, a compact disk, a mobile disk, a magnetic tape, a database accessible to networks, or any other storage media with the same function and well known to those skilled in the art.
Referring first to
Next, step S305 is executed to confirm that the mobile node is now within the first signal coverage according to the received positioning information to generate a confirmation result. Step S306 is executed to retrieve the broadcast overhead information, the communication path information and the updated probability information from the updated statistics table according to the confirmation result. Subsequently, step S307 is executed to generate a calculation result relating to the second access point according to the updated probability information, the broadcast overhead information and the communication path information.
Referring to
If the determination result indicates that the acknowledgement receiving result is received during the specific time period, then step S311 is executed to determine that the burst has been certainly received by the mobile node according to the receipt acknowledgement signal. Otherwise, if the determination result indicates that the acknowledgement receiving result is not received during the specific time period, then step S312 is executed to transmit the burst through broadcast according to the determination result so that the mobile node may receive the burst via one of the first access point and the second access point.
In addition to the aforesaid steps, the second embodiment can also execute all the operations and functions set forth in the first embodiment. How the second embodiment executes these operations and functions will be readily appreciated by those of ordinary skill in the art based on the explanation of the first embodiment, and thus will not be further described herein.
In summary, the present invention provides a solution for wireless communication. According to this solution, access points in possible moving paths of a mobile node are known from a statistics table, and then signal transmissions (i.e., burst transmissions) to the mobile node are carried out through multicast via the access points in the possible moving paths. This solution may not only provide mobile nodes in the wireless network with good wireless communication quality, but also reduce unnecessary consumption of wireless network resources and usage of register space resources of access points.
The above disclosure is related to the detailed technical contents and inventive features thereof. People skilled in this field may proceed with a variety of modifications and replacements based on the disclosures and suggestions of the invention as described without departing from the characteristics thereof. Nevertheless, although such modifications and replacements are not fully disclosed in the above descriptions, they have substantially been covered in the following claims as appended.
| Number | Date | Country | Kind |
|---|---|---|---|
| 098119519 | Jun 2009 | TW | national |
