Data transmission method using multiple wireless networks

Abstract

Data transmission method includes a first mobile device linking a first wireless network with a first linking quality and a second wireless network with a second linking quality. The first mobile device acquires a sum of first bandwidth requirements and a sum of second bandwidth requirements of application programs currently running. The first mobile device acquires a bandwidth allocation result according to the first linking quality, the second linking quality, the sum of first bandwidth requirements, and the sum of second bandwidth requirements. The first mobile device performs data link to the first wireless network and/or the second wireless network according to the bandwidth allocation result, and then performs data transmission of the application programs. The sum of second bandwidth requirements is greater than the sum of first bandwidth requirements. The bandwidth allocation result corresponds to a bandwidth usage value for all application programs.

Claims

1. A data transmission method comprising: linking a first mobile device to a first wireless network with a first linking quality; linking the first mobile device to a second wireless network with a second linking quality; acquiring a sum of first bandwidth requirements of application programs currently running in the first mobile device; acquiring a sum of second bandwidth requirements of application programs currently running in the first mobile device; acquiring a bandwidth allocation result according to the first linking quality, the second linking quality, the sum of first bandwidth requirements, and the sum of second bandwidth requirements by the first mobile device; establishing a data link to the first wireless network and/or the second wireless network from the first mobile device according to the bandwidth allocation result; and performing data transmission between the application programs and the first wireless network and/or the second wireless network; wherein the sum of second bandwidth requirements is greater than the sum of first bandwidth requirements, the bandwidth allocation result corresponds to a value of bandwidth utilization, and the value of bandwidth utilization is between the sum of first bandwidth requirements and the sum of second bandwidth requirements.

2. The data transmission method of claim 1, further comprising: disabling a running application program and enabling a new application program selectively; updating the sum of first bandwidth requirements and the sum of second bandwidth requirements; acquiring an updated bandwidth allocation result according to the first linking quality, the second linking quality, an updated sum of first bandwidth requirements, an updated sum of second bandwidth requirements; and reallocating the updated sum of first bandwidth requirements and the updated sum of second bandwidth requirements to the first wireless network and/or the second wireless network according to the updated bandwidth allocation result.

3. The data transmission method of claim 1, wherein acquiring the sum of first bandwidth requirements of the first mobile device is acquiring the sum of first bandwidth requirements according to a utilization priority of the application programs currently running in the first mobile device.

4. The data transmission method of claim 1, wherein establishing the data link to the first wireless network and/or the second wireless network from the first mobile device according to the bandwidth allocation result comprises: when the first linking quality is better than the second linking quality, and a sum of maximum bandwidths of the first wireless network and the second wireless network is smaller than the sum of second bandwidth requirements, the first mobile device selecting the first wireless network for establishing the data link and performs data transmission of the application programs by using the sum of first bandwidth requirements.

5. The data transmission method of claim 1, wherein the sum of first bandwidth requirements is a sum of minimum bandwidth requirements of the application programs currently running, and the sum of second bandwidth requirements is a sum of maximum bandwidth requirements of the application programs currently running.

6. The data transmission method of claim 1, wherein the application programs currently running comprise a foreground application program and a background application program, and establishing the data link to the first wireless network and/or the second wireless network from the first mobile device according to the bandwidth allocation result comprises: the first mobile device selecting a network with a better linking quality from the first wireless network and the second wireless network according to the first linking quality and the second linking quality; and allocating a bandwidth of a selected network to the foreground application program; wherein the background application program is selectively allocated with a bandwidth of the first wireless network or a bandwidth of the second wireless network.

7. The data transmission method of claim 6, wherein the first bandwidth requirements comprises a utilization bandwidth of the foreground application program and a minimum background bandwidth requirement of the background application program, and the second bandwidth requirements comprises a maximum foreground bandwidth requirement of the foreground application program and a maximum background bandwidth requirement of the background application program.

8. The data transmission method of claim 7, wherein when the foreground application program establishes a data link by using the utilization bandwidth equal to a minimum foreground bandwidth requirement, the foreground application program performs media data transmission with a first resolution, when the foreground application program establishes the data link by using the utilization bandwidth equal to the maximum foreground bandwidth requirement, the foreground application program performs media data transmission with a second resolution, and the second resolution is higher than the first resolution.

9. The data transmission method of claim 1, further comprising: linking a plurality of mobile devices to the first wireless network, wherein the plurality of mobile devices include the first mobile device, each mobile device of the plurality of mobile devices having a sum of first minimum bandwidth requirements and a sum of first maximum bandwidth requirements; linking a second mobile device to the first wireless network for running a first application program; acquiring a sum of second minimum bandwidth requirements and a sum of second maximum bandwidth requirements of the second mobile device; and when a sum of the sum of second minimum bandwidth requirements and a sum of first minimum bandwidth requirements of the plurality of mobile devices is greater than a first predetermined value, decreasing a sum of first minimum bandwidth requirements of at least one mobile device selected from the plurality of mobile devices.

10. The data transmission method of claim 1, further comprising: linking a plurality of mobile devices to the first wireless network, wherein the plurality of mobile devices comprise the first mobile device, each mobile device of the plurality of mobile devices having a sum of first minimum bandwidth requirements and a sum of first maximum bandwidth requirements; linking a second mobile device to the first wireless network for running a first application program; acquiring a sum of second minimum bandwidth requirements and a sum of second maximum bandwidth requirements of the second mobile device; and when a sum of the sum of second minimum bandwidth requirements and a sum of first minimum bandwidth requirements of the plurality of mobile devices is greater than a first predetermined value, disabling data transmission of the first application program in the second mobile device through the first wireless network.

11. The data transmission method of claim 10, further comprising: linking the plurality of mobile devices to the second wireless network; linking the second mobile device to the second wireless network; and when a sum of the sum of second maximum bandwidth requirements and a sum of first maximum bandwidth requirements of the plurality of mobile devices is greater than a second predetermined value, limiting a utilization bandwidth of the second mobile device.

12. A data transmission method comprising: linking a plurality of mobile devices to a first wireless network; acquiring a sum of minimum bandwidth requirements of application programs currently running in each mobile device; acquiring a sum of maximum bandwidth requirements of application programs currently running in each mobile device; linking an external mobile device to the first wireless network; acquiring a sum of external minimum bandwidth requirements of application programs currently running in the external mobile device; acquiring a sum of external maximum bandwidth requirements of application programs currently running in the external mobile device; and adjusting a utilization bandwidth of the external mobile device according to a sum of minimum bandwidth requirements of the plurality of mobile devices, a sum of maximum bandwidth requirements of the plurality of mobile devices, the sum of external minimum bandwidth requirements of the external mobile device, and/or the sum of external maximum bandwidth requirements of the external mobile device; wherein the plurality of mobile devices are exclusive of the external mobile device, the external mobile device is disconnected before the external mobile device is linked to the first wireless network.

13. The data transmission method of claim 12, further comprising: generating and registering a bandwidth allocation result by using a resource management device according to the sum of minimum bandwidth requirements and the sum of maximum bandwidth requirements of each mobile device; and registering the sum of external minimum bandwidth requirements of the external mobile device and the sum of external maximum bandwidth requirements of the external mobile device to the resource management device; wherein adjusting the utilization bandwidth of the external mobile device is adjusting the utilization bandwidth of the external mobile device by using the resource management device.

14. The data transmission method of claim 12, wherein adjusting the utilization bandwidth of the external mobile device according to the sum of minimum bandwidth requirements of the plurality of mobile devices, the sum of maximum bandwidth requirements of the plurality of mobile devices, the sum of external minimum bandwidth requirements of the external mobile device, and/or the sum of external maximum bandwidth requirements of the external mobile device comprises: when a sum of the sum of external minimum bandwidth requirements of the external mobile device and a sum of minimum bandwidth requirements of the plurality of mobile devices is greater than a predetermined value, decreasing a sum of bandwidth requirements of at least one mobile device selected from the plurality of mobile devices.

15. The data transmission method of claim 14, wherein a decreasing amount of the sum of bandwidth requirements of at least one mobile device selected from the plurality of mobile devices corresponds to a value of linking contribution, and the value of linking contribution contributes to an increase of a priority value of bandwidth utilization when the at least one mobile device accesses the first wireless network again.

16. The data transmission method of claim 12, wherein adjusting the utilization bandwidth of the external mobile device according to the sum of minimum bandwidth requirements of the plurality of mobile devices, the sum of maximum bandwidth requirements of the plurality of mobile devices, the sum of external minimum bandwidth requirements of the external mobile device, and/or the sum of external maximum bandwidth requirements of the external mobile device comprises: when a sum of the sum of external minimum bandwidth requirements of the external mobile device and a sum of minimum bandwidth requirements of the plurality of mobile devices is greater than a predetermined value, disabling data transmissions of all application programs in the external mobile device through the first wireless network.

17. The data transmission method of claim 12, further comprising: linking the plurality of mobile devices to a second wireless network; linking the external mobile device to the second wireless network; and when a sum of the sum of external maximum bandwidth requirements of the external mobile and a sum of maximum bandwidth requirements of the plurality of mobile devices is greater than a predetermined value, limiting a utilization bandwidth of the external mobile device, wherein the application programs currently running in each mobile device comprises a foreground application program and a background application program, each mobile device selects a network with a better linking quality from the first wireless network and the second wireless network, each mobile device allocates a bandwidth of a selected network to the foreground application program, and the background application program is selectively allocated with a bandwidth of the first wireless network or a bandwidth of the second wireless network.

18. A data transmission method comprising: linking a plurality of mobile devices to a first wireless network, each mobile device of the plurality of mobile devices having a bandwidth utilized by at least one application program; and acquiring a sum of bandwidths utilized by the plurality of mobile devices; wherein when the sum of bandwidths utilized by the plurality of mobile devices is greater than a predetermined value, a limitation message is broadcasted to the plurality of mobile devices through the first wireless network for limiting bandwidths utilized by a portion of the plurality of mobile devices, and the bandwidths utilized by the portion of the plurality of mobile devices are decreased to be lower than an upper bound.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 illustrates a block diagram of a data transmission system according to an embodiment of the present invention.

(2) FIG. 2 illustrates a block diagram of a bandwidth allocation method of the data transmission system in FIG. 1.

(3) FIG. 3 illustrates a block diagram of a data transmission system according to another embodiment of the present invention.

DETAILED DESCRIPTION

(4) FIG. 1 illustrates a block diagram of a data transmission system 100 according to an embodiment of the present invention. The data transmission system 100 comprises a mobile device UE.sub.1, a first network NTAT.sub.1, a second network NW.sub.2, a content provider CTP, and a resource management device RM. The mobile device UE.sub.1 may establish a wireless link to a base station of the first network NW.sub.1 through a first path L.sub.1. The mobile device UE.sub.1 may establish a wireless link to a base station of the second network NW.sub.2 through a second path L2. The mobile device UE.sub.1 may have an internal routing policy manager RPM and a list S listing application programs AP.sub.1 to AP.sub.N currently running. The resource management device RM and the content provider CTP are linked to the first network NW.sub.1 and the second network NW.sub.2. Each of the first network NW.sub.1 and the second network NW.sub.2 is a heterogeneous network. However, the embodiment presented having the first network NW.sub.1 and the second network NW.sub.2 is only an exemplary embodiment and is not meant to limit the scope of the invention. The resource management device RM and the content provider CTP may link to more than two heterogeneous networks instead. Furthermore, the resource management device RM and/or the content provider CTP are not limited to being linked to the first network NW.sub.1 and the second network NW.sub.2 from outside the mobile device UE.sub.1. The resource management device RM and/or the content provider CTP may be built-in devices of the mobile device UE.sub.1. The application programs AP.sub.1, AP.sub.2, to AP.sub.N currently running in the mobile device UE.sub.1 may each have a different bandwidth requirement. The mobile device UE.sub.1 may first separately acquire the linking quality of the link to the first network NW.sub.1 through the first path L.sub.1 and the linking quality of the link to the second network NW.sub.2 through the second path L.sub.2. After determining the bandwidth requirement of each of the application programs AP.sub.1 to AP.sub.N currently running, a bandwidth allocation result may be generated. Afterwards, the mobile device UE.sub.1 may establish a data link to the first network NW.sub.1 and/or the second network NW.sub.2 according to the bandwidth allocation result and perform data transmission of each of the application programs AP.sub.1 to AP.sub.N currently running. Therefore, the bandwidth used by each of the application programs AP.sub.1, AP.sub.2, to AP.sub.N currently running may be the optimal allocation of bandwidth provided by the two heterogeneous networks (NW.sub.1 and NW.sub.2) and, in doing so, improve transmission speed. The following paragraphs will further describe the bandwidth allocation method.

(5) FIG. 2 illustrates a block diagram of a bandwidth allocation method of the data transmission system in FIG. 1. As shown in FIG. 2, the mobile device UE.sub.1 may consider the bandwidth requirement of each of the N application programs AP.sub.1 to AP.sub.N currently running. In the embodiment, the bandwidth requirement of each of N application programs AP.sub.1 to AP.sub.N currently running may be divided into two categories. The first category may contain minimum bandwidth requirements of the application programs AP.sub.1 to AP.sub.N. The second category may contain maximum bandwidth requirements of the application programs AP.sub.1 to AP.sub.N, also known as the optimal bandwidths. As shown in FIG. 2, the minimum bandwidth requirements of application programs AP.sub.1 to AP.sub.N may respectively be C.sub.1 to C.sub.N. The maximum bandwidth requirements of application programs AP.sub.1 to AP.sub.N may respectively be V.sub.1 to V.sub.N. Each of the minimum bandwidth requirements C.sub.1 to C.sub.N may be the bandwidth required by a corresponding application program during updating, positioning, and/or periodically reporting or the minimum bandwidth required when the application program is a foreground application program. Each of the maximum bandwidth requirements V.sub.1 to V.sub.N may be the bandwidth used for data transmission at a maximum speed or the bandwidth required by a high resolution multimedia application program. The routing policy manager RPM of the mobile device UE.sub.1 may be used to obtain a sum C of the minimum bandwidth requirements and a sum V of the maximum bandwidth requirements of the application programs AP.sub.1 to AP.sub.N. The sum C is the summation of the minimum bandwidth requirements C.sub.1, C.sub.2, to C.sub.N, as

(6) $C=\underset{n=1}{\overset{N}{.Math.}}{C}_n.$
The sum V is the summation of the maximum bandwidth requirements V.sub.1 to V.sub.N, as

(7) $V=\underset{n=1}{\overset{N}{.Math.}}{V}_n.$
The routing policy manager RPM may acquire the linking qualities of the links of the network interfaces NWD.sub.1 to NWD.sub.M of the mobile device UE.sub.1 to the corresponding networks. As compared to FIG. 1, if the states of the first network NW.sub.1 and the second network NW.sub.2 are being considered, the routing policy manager RPM may determine the linking quality LQ.sub.1 of the link of the mobile device UE.sub.1 to the first network NW.sub.1 through the first path L.sub.1 and the linking quality LQ.sub.2 of the link of the mobile device UE.sub.1 to the second network NW.sub.2 through the second path L.sub.2. The present invention may consider the states of M heterogeneous networks. As shown in FIG. 2, when considering M heterogeneous networks, the routing policy manager RPM may acquire M linking qualities LQ.sub.1 to LQ.sub.M, wherein N and M are positive integers. The first network NW.sub.1 and the second network NW.sub.2 may be used as example for the description. According to the embodiment, the linking quality LQ.sub.1 of the first network NW.sub.1 and the linking quality LQ.sub.2 of the second network NW.sub.2 may be defined using any measurement related to a network, for example, transmission rate, transmission delay, packet error rate, power consumption and/or cost. The routing policy manager RPM may use an objective function to generate the bandwidth allocation result according to the abovementioned measurements related to the networks. For example, when the user wants to optimize all the application programs AP.sub.1 to AP.sub.N currently running according to transmission delays, the routing policy manager RPM may consider the transmission delays (measured by the content provider CTP) when acquiring the linking quality LQ.sub.1 of the first network NW.sub.1 and the linking quality LQ.sub.2 of the second network NW.sub.2. When the user wants to optimize all the application programs AP.sub.1 to AP.sub.N currently running according to transmission speeds, the routing policy manager RPM may consider the transmission speeds when acquiring the linking quality LQ.sub.1 of the first network NW.sub.1 and the linking quality LQ.sub.2 of the second network NW.sub.2. The description below discloses how the mobile device UE.sub.1 allocates the bandwidths used by the application programs AP.sub.1 to AP.sub.N currently running to the first network NW.sub.1 and the second network NW.sub.2.

(8) An example is used to describe the method of allocation of bandwidths used by the application programs AP.sub.1 to AP.sub.N currently running to the first network NW.sub.1 and the second network NW.sub.2 by the mobile device UE.sub.1. The status of the mobile device UE.sub.1 may be set first. The application programs AP.sub.1 to AP.sub.N currently running on the mobile device UE.sub.1 may have the application program AP.sub.1 be a foreground program and the application programs AP.sub.2 to AP.sub.N be background programs. Therefore, the routing policy manager RPM may obtain the sum C of the minimum bandwidth requirements. The sum C is defined as the summation of the foreground minimum bandwidth requirement C.sub.1 of the foreground application program AP.sub.1 and the background minimum bandwidth requirements C.sub.2 to C.sub.N of the background application programs

(9) ${\mathrm{AP}}_2\mathrm{to}{\mathrm{AP}}_N\left(C=\underset{n=1}{\overset{N}{.Math.}}{C}_n\right).$
The routing policy manager RPM may obtain the sum V of the maximum bandwidth requirements. The sum V is defined as the summation of the foreground maximum bandwidth requirement V.sub.1 of the foreground application programs AP.sub.1 and the background maximum bandwidth requirements V.sub.2 to V.sub.N of the background application programs

(10) ${\mathrm{AP}}_2\mathrm{to}{\mathrm{AP}}_N\left(V=\underset{n=1}{\overset{N}{.Math.}}{V}_n\right).$
The foreground application program AP.sub.1 may be the application program currently being used by the user on the screen and may have a higher priority. The background application programs AP.sub.2 to AP.sub.N may be application programs hidden in the background of the operating system of the mobile device UE.sub.1 or resident programs. According to the embodiment, the sum V of the maximum bandwidth requirements is greater than the sum C of the minimum bandwidth requirements. For the foreground application program AP.sub.1 the foreground maximum bandwidth requirement V.sub.1 is greater than the foreground minimum bandwidth requirement C.sub.1. For example, when the foreground application program AP.sub.1 uses the foreground maximum bandwidth requirement V.sub.1 for linking, the user may be using high resolution multimedia in the data transmission. In the contrary, when the foreground application program AP.sub.1 uses the foreground minimum bandwidth requirement C.sub.1 for linking, the user may be using low resolution multimedia in the data transmission. The routing policy manager RPM may determine the linking quality LQ.sub.1 of the first network NW.sub.1 and the linking quality LQ.sub.2 of the second network NW.sub.2. The routing policy manager RPM may generate the bandwidth allocation result according to the linking quality LQ.sub.1 of the first network NW.sub.1, the linking quality LQ.sub.2 of the second network NW.sub.2, the sum V of the maximum bandwidth requirements, and the sum C of the minimum bandwidth requirements. The bandwidth allocation result may be used for establishing a data link to the first network NW.sub.1 and/or the second network NW.sub.2 and perform data transmission for application programs AP.sub.1 to AP.sub.N. For example, if the linking quality LQ.sub.1 of the first network NW.sub.1 is better than the linking quality LQ.sub.2 of the second network NW.sub.2, the routing policy manager RPM may allocate the bandwidth of the first network NW.sub.1 to the foreground application program AP.sub.1 and the background application programs AP.sub.2 to AP.sub.N may selectively use the bandwidths of the first network NW.sub.1 and the second network NW.sub.2. And, when the total bandwidth NWB.sub.1 provided by the first network NW.sub.1 and the total bandwidth NWB.sub.2 provided by the second network NW.sub.2 are both greater than or equal to the sum V of the maximum bandwidth requirements, the bandwidth of the foreground application program AP.sub.1 may be allocated to the first network NW.sub.1 having a better linking quality (high transmission speed, low transmission delay, low packet error rate, etc.) to ensure that the foreground application program AP.sub.1 may smoothly connect to the internet when being used by the user. The background application programs AP.sub.2 to AP.sub.N may selectively use the bandwidths of the first network NW.sub.1 (if the first network has free bandwidth) and the second network NW.sub.2 to ensure that the linking qualities for the background application programs AP.sub.2 to AP.sub.N are maintained at a certain level. However, the present invention is not limited to the abovementioned embodiment. When the linking quality LQ.sub.1 of the first network NW.sub.1 is much better than the linking quality LQ.sub.2 of the second network NW.sub.2, the routing policy manager RPM may allocate the bandwidth of the first network NW.sub.1 to the foreground application program AP.sub.1 and the background application programs AP.sub.2 to AP.sub.N. According to the bandwidth properties (according to the minimum bandwidth requirements and the maximum bandwidth requirements) of the application programs AP.sub.1 to AP.sub.N, the bandwidth requirements are dynamically allocated to several different heterogeneous networks (i.e. the first network NW.sub.1 and the second network NW.sub.2). The method of using bandwidths of several heterogeneous networks simultaneously may not only increase the channel capacity but also increase the data transmission rate.

(11) According to the embodiment, the bandwidth requirements of the foreground application program AP.sub.1 and the background application programs AP.sub.2 to AP.sub.N may be determined in real time or may be determined periodically. When the user selectively terminates a currently running application program AP.sub.1 and executes a new application program AP.sub.1 in the mobile device UE.sub.1, the routing policy manager RPM may determine bandwidth requirements of a new foreground application program AP.sub.1 and new background application programs AP.sub.2 to AP.sub.N. Therefore, the sum C of the minimum bandwidth requirements and the sum V of the maximum bandwidth requirements may be updated. In the same way as the method of allocation of bandwidths described above, the routing policy manager RPM may generate a new bandwidth allocation result according to the linking quality LQ.sub.1 of the first network NW.sub.1, the linking quality LQ.sub.2 of the second network NW.sub.2, the updated sum V of the maximum bandwidth requirements, and the updated sum C of the minimum bandwidth requirements. The new bandwidth allocation result may be used for establishing a data link to the first network NW.sub.1 and/or the second network NW.sub.2 and perform data transmission for application programs AP.sub.1 to AP.sub.N. Therefore, when bandwidths of the application programs currently running in the mobile device UE.sub.1 change, the routing policy manager RPM may measure the bandwidth variations in real-time and reallocate the bandwidths for the first network NW.sub.1 and the second network NW.sub.2. Furthermore, according to FIG. 1, the mobile device UE.sub.1 may use the resource management device RM linked to the first network NW.sub.1 and the second network NW.sub.2 to perform bandwidth allocation. The bandwidth allocation to be performed may be the same as the bandwidth allocation disclosed above. The difference may be in that the mobile device UE.sub.1 may report the bandwidths used (including the sum C of the minimum bandwidth requirements and the sum V of the maximum bandwidth requirements) by the application programs currently running to the resource management device RM. The resource management device RM may then perform bandwidth allocation for all the application programs currently running in the mobile device UE.sub.1 according to the sum V of the maximum bandwidth requirements, the sum C of the minimum bandwidth requirements, the linking quality LQ.sub.1 of the first network NW.sub.1, and the linking quality LQ.sub.2 of the second network NW.sub.2. By using a plurality of heterogeneous networks, the present invention may be used to increase the data transmission rate of media/video data stream. For example, the foreground application program AP.sub.1 may be a media/video data stream program, such as YouTube. The mobile device UE.sub.1 may divide the video data to several time intervals of discrete video data. For example, the first time interval may be 0 to 1 minute of video data, the second time interval may be 1 to 2 minutes of video data and so on. The mobile device UE.sub.1 may allocate a bandwidth for the foreground application program AP.sub.1 and, at the same time, transmit the video data of the first time interval using the first network NW.sub.1 and transmit the video data of the second time interval using the second network NW.sub.2. In this embodiment, the data bandwidth may be divided to the first network NW.sub.1 and the second network NW.sub.2. The bandwidths of the two networks may simultaneously be used to access and transmit data. Therefore, the problem of not being able to transmit video data due to bandwidth limitation of a single network such as the first network NW.sub.1 and the second network NW.sub.2 can be resolved. Furthermore, if the linking qualities of the first network NW.sub.1 and the second network NW.sub.2 are similar, the data transmission time of the application program AP.sub.1 may be reduced to approximately half of the original. Because time division multiplexing through two heterogeneous networks can be used for the data transmission, there is an increase of timing utilization rate for each of the networks as compared to a data transmission system with only one network. Thus, the present invention can mitigate traffic congestion during data transmission.

(12) The following is a description of a method of allocating bandwidths for a plurality of mobile devices. FIG. 3 illustrates a block diagram of a data transmission system 200 according to another embodiment of the present invention. The data transmission system 200 may consider the status of X mobile devices and two heterogeneous networks. In FIG. 3, the data transmission system 200 includes a first mobile device UE.sub.1 to X.sup.th mobile device UE.sub.X, a first network NW.sub.1, a second network NW.sub.2, a content provider CTP, and a resource management device RM. Aside from the X.sup.th mobile device UE.sub.X, the remaining (X1) mobile devices UE.sub.1 to UE.sub.X-1 may be within the network coverage of the first network NW.sub.1 and the second network NW.sub.2. The X.sup.th mobile device UE.sub.X may be an external mobile device and may link to the first network NW.sub.1 and the second network NW.sub.2. For presentation simplicity, in the following disclosure, the first to (X1).sup.th mobile devices UE.sub.1 to UE.sub.X-1 may be referred to as mobile devices UE.sub.1 to UE.sub.X-1 and the X.sup.th mobile device UE.sub.X may be referred to as mobile device UE.sub.X. The mobile device UE.sub.1 may link to the first network NW.sub.1 through a path L.sub.21 and link to the second network NW.sub.2 through a path L.sub.22. The mobile device UE.sub.2 may link to the first network NW.sub.1 through a path L.sub.21 and link to the second network NW.sub.2 through a path L.sub.22. Similarly, the mobile device UE.sub.X-1 may link to the first network NW.sub.1 and link to the second network NW.sub.2 through different respective paths. The external mobile device UE.sub.X may link to the first network NW.sub.1 through a path L.sub.X1 and link to the second network NW.sub.2 through a path L.sub.X2. In the embodiment, the mobile devices UE.sub.1 to UE.sub.X may each have a respective internal routing policy manager RPM.sub.1 to RPM.sub.X and a respective list S.sub.1 to S.sub.X listing application programs currently running. The list S.sub.1 may list application programs AP.sub.11 to AP.sub.1N1 currently running in the mobile device UE.sub.1. The list S.sub.2 may list application programs AP.sub.21 to AP.sub.2N2 currently running in the mobile device UE.sub.2. In the same way, the list S.sub.X may list application programs AP.sub.X1 to AP.sub.XNX currently running in the mobile device UE.sub.X. The respective internal routing policy managers RPM.sub.1 to RPM.sub.X of the mobile devices UE.sub.1 to UE.sub.X function in the same way as in the embodiment shown in FIG. 2, thus, it will no longer be described for brevity. The resource management device RM and the content provider CTP are linked to the first network NW.sub.1 and the second network NW.sub.2. Each of the first network NW.sub.1 and the second network NW.sub.2 is a heterogeneous network. However, the embodiment presented having the first network NW.sub.1 and the second network NW.sub.2 is only an exemplary embodiment and is not meant to limit the scope of the invention. The resource management device RM and the content provider CTP may link to more than two heterogeneous networks instead. Furthermore, the resource management device RM and/or the content provider CTP may be built within the circuit of a mobile device. Each of the application programs currently running in a respective mobile device UE.sub.1 to UE.sub.X uses a corresponding bandwidth. The routing policy manager of a mobile device may acquire the bandwidth requirement of the application programs currently running in the mobile device. For example, the routing policy manager RPM.sub.1 of the mobile device UE.sub.1 may acquire the sum C(1) of the minimum bandwidth requirements and the sum. V(1) of the maximum bandwidth requirements of the application programs AP.sub.11 to AP.sub.1N1 currently running. Similar to FIG. 1, the sum C(1) is the summation of the minimum bandwidth requirements C.sub.11 to C.sub.1N1 of the application programs AP.sub.11 to AP.sub.1N1 currently running, as

(13) $C\left(1\right)=\underset{n=1}{\overset{N_1}{.Math.}}{C}_{1n}.$
The sum V(1) is the summation the maximum bandwidth requirements V.sub.11 to V.sub.1N1 of the application programs AP.sub.11 to AP.sub.1N1 currently running, as

(14) $V\left(1\right)=\underset{n=1}{\overset{N_1}{.Math.}}{V}_{1n}.$
In the same way, the routing policy manager RPM.sub.2 of the mobile device UE.sub.2 may acquire the sum C(2) of the minimum bandwidth requirements and the sum V(2) of the maximum bandwidth requirements of the application programs AP.sub.21 to AP.sub.2N2 currently running. The sum C(2) is the summation of the minimum bandwidth requirements C.sub.21 to C.sub.2N2 of the application programs AP.sub.21 to AP.sub.2N2 currently running, as

(15) $C\left(2\right)=\underset{n=1}{\overset{N_2}{.Math.}}{C}_{2n}.$
The sum V(2) is the summation of the maximum bandwidth requirements V.sub.21 to V.sub.2N2 of the application programs AP.sub.21 to AP.sub.2N2 currently running, as

(16) $V\left(2\right)=\underset{n=1}{\overset{N_2}{.Math.}}{V}_{2n}.$
The routing policy manager RPM.sub.X of the external mobile device UE.sub.X may acquire the sum C(X) of the minimum bandwidth requirements and the sum. V(X) of the maximum bandwidth requirements of the application programs AP.sub.X1 to AP.sub.XNX currently running. The sum C(X) is the summation of the minimum bandwidth requirements C.sub.X1 to C.sub.XNX of the application programs AP.sub.X1 to AP.sub.XNX currently running, as

(17) $C\left(X\right)=\underset{n=1}{\overset{N_X}{.Math.}}{C}_{\mathrm{Xn}}.$
The sum V(X) is the summation of the maximum bandwidth requirements V.sub.X1 to V.sub.XNX of the application programs AP.sub.X1 to AP.sub.XNX currently running, as

(18) 0$V\left(X\right)=\underset{n=1}{\overset{N_X}{.Math.}}{V}_{\mathrm{Xn}}.$
In the embodiment, the sums of bandwidth requirements acquired by each of the mobile devices may be announced (i.e. an application program may be used to share a bandwidth requirement result to other mobile devices). Therefore, when the external mobile device UE.sub.X establishes a data link to the first network NW.sub.1 and the second network NW.sub.2 (that is sending a request for data link), all of the mobile devices UE.sub.1 to UE.sub.X may start coordinating such that the bandwidth allocation for the mobile devices UE.sub.1 to UE.sub.X-1 and the external mobile device UE.sub.X within the network coverage may be optimized. The following paragraph includes a description of the method for allocating bandwidths of the mobile devices UE.sub.1 to UE.sub.X-1 and the method for allocating bandwidth of the external mobile device UE.sub.X.

(19) An example is used to describe the bandwidth allocation process for the data transmission system 200 and, more particularly, describe a method of allocating bandwidths of the mobile devices UE.sub.1 to UE.sub.X of the data transmission system 200 under different condition. The following several bandwidth conditions may be considered: (A) When the external mobile device UE.sub.X establishes a data link with the first network NW.sub.1 and the second network NW.sub.2 and the bandwidth requirements for the mobile devices UE.sub.1 to UE.sub.X measured by the data transmission system 200 satisfy the condition

(20) $\underset{i=1}{\overset{X}{.Math.}}C\left(i\right)>{\mathrm{NWB}}_1$
wherein NWB.sub.1 denotes the maximum bandwidth of the first network NW.sub.1, all of the mobile devices UE.sub.1 to UE.sub.X may use the linking speed for the minimum bandwidth requirement. In this case, the first network NW.sub.1 may not be able to support the additional linking of the external mobile device UE.sub.X (i.e. first network NW.sub.1 may overload). Therefore, the data transmission system 200 may forbid the external mobile device UE.sub.X from using the first network NW.sub.1 to transmit data. Similarly, when the mobile devices UE.sub.1 to UE.sub.X of data transmission system 200 satisfy the condition

(21) $\underset{i=1}{\overset{X}{.Math.}}C\left(i\right)>{\mathrm{NWB}}_2$
wherein NWB.sub.2 denotes the maximum bandwidth of the second network NW.sub.2, the data transmission system 200 may forbid the external mobile device UE.sub.X from using the second network NW.sub.2 to transmit data. (B) When the external mobile device UE.sub.X establishes a data link with the first network NW.sub.1 and the second network NW.sub.2 and the bandwidth requirements for the mobile devices UE.sub.1 to UE.sub.X measured by data transmission system 200 satisfy the condition

(22) $\underset{i=1}{\overset{X}{.Math.}}C\left(i\right){\mathrm{NWB}}_1$
and

(23) $\underset{i=1}{\overset{X}{.Math.}}V\left(i\right)>{\mathrm{NWB}}_1$
wherein NWB.sub.1 denotes the maximum bandwidth of the first network NW.sub.1. In this case, the first network NW.sub.1 may be able to deal with bandwidths of all of the application programs currently running in the mobile devices UE.sub.1 to UE.sub.X by using minimum bandwidth requirements. Specifically, the first network NW.sub.1 may not be able to load the addition bandwidth of the external mobile device UE.sub.X operating using maximum bandwidth when the bandwidths of all of the application programs currently running in the mobile devices UE.sub.1 to UE.sub.X-1 within the network coverage are using maximum bandwidth requirements. Therefore, the data transmission system 200 may limit the bandwidth used by the external mobile device UE.sub.X in the first network NW.sub.1. Similarly, when the mobile devices UE.sub.1 to UE.sub.X of data transmission system 200 satisfy the condition

(24) $\underset{i=1}{\overset{X}{.Math.}}C\left(i\right){\mathrm{NWB}}_2\mathrm{and}\underset{i=1}{\overset{X}{.Math.}}V\left(i\right)>{\mathrm{NWB}}_2$
wherein NWB.sub.2 denotes the maximum bandwidth of the second network NW.sub.2, the data transmission system 200 may limit the bandwidth used by the external mobile device UE.sub.X in the second network NW.sub.2. (C) When the external mobile device UE.sub.X establishes a data link with the first network NW.sub.1 and the second network NW.sub.2 and the bandwidth requirements for the mobile devices UE.sub.1 to UE.sub.X measured by data transmission system 200 satisfy the condition

(25) $\underset{i=1}{\overset{X}{.Math.}}V\left(i\right){\mathrm{NWB}}_1$
wherein NWB.sub.1 denotes the maximum bandwidth of the first network NW.sub.1, the

(26) $\underset{i=1}{\overset{X}{.Math.}}V\left(i\right)$
may be greater than

(27) $\underset{i=1}{\overset{X}{.Math.}}C\left(i\right).$
Therefore, the condition

(28) $\underset{i=1}{\overset{X}{.Math.}}V\left(i\right){\mathrm{NWB}}_1$
meets the condition

(29) 0$\underset{i=1}{\overset{X}{.Math.}}C\left(i\right){\mathrm{NWB}}_1.$
In this case, the first network NW.sub.1 may not only be able to load all bandwidths with respect to all of the application programs currently running in the mobile devices UE.sub.1 to UE.sub.X using minimum bandwidth requirements, but also all of the application programs currently running in the mobile devices UE.sub.1 to UE.sub.X using maximum bandwidth requirements. Therefore, the data transmission system 200 may allow the external mobile device UE.sub.X to use the first network NW.sub.1 for data transmission. Also, each of the mobile devices UE.sub.1 to UE.sub.X-1 and the external mobile device UE.sub.X may use respective optimal bandwidth allocation result to establish links. Similarly, when the mobile devices UE.sub.1 to UE.sub.X of data transmission system 200 satisfy the condition

(30) $\underset{i=1}{\overset{X}{.Math.}}V\left(i\right){\mathrm{NWB}}_2$
wherein NWB.sub.2 denotes the maximum bandwidth of the second network NW.sub.2, the data transmission system 200 may allow the external mobile device UE.sub.X to use the second network NW.sub.2 for data transmission. (D) When the external mobile device UE.sub.X establishes a data link with the first network NW.sub.1 and the second network NW.sub.2 and the bandwidth requirements for the mobile devices UE.sub.1 to UE.sub.X measured by data transmission system 200 satisfy the condition

(31) $\underset{i=1}{\overset{X}{.Math.}}C\left(i\right)>{\mathrm{NWB}}_1$
wherein NWB.sub.1 denotes the maximum bandwidth of the first network NW.sub.1, even though all of the mobile devices UE.sub.1 to UE.sub.X may use the speed for minimum bandwidth requirement for linking, the first network NW.sub.1 may not load the additional bandwidth of the external mobile device UE.sub.X (i.e. first network NW.sub.1 may overload). The transmission system 200 may adjust the sum of the minimum bandwidth requirements of the application programs of at least one of the mobile devices UE.sub.1 to UE.sub.X-1 within the network coverage. In other words, the bandwidth requirement

(32) $\underset{i=1}{\overset{X-1}{.Math.}}C\left(i\right)$
may be reduced to allow the external mobile device UE.sub.X to use the first network NW.sub.1 to transmit data. Similarly, when the bandwidth requirements for the mobile devices UE.sub.1 to UE.sub.X measured by data transmission system 200 satisfy the condition

(33) $\underset{i=1}{\overset{X}{.Math.}}C\left(i\right)>{\mathrm{NWB}}_2$
wherein NWB.sub.2 denotes the maximum bandwidth of the second network NW.sub.2, the transmission system 200 may adjust the sum of the minimum bandwidth requirements of the application programs of at least one of the mobile devices UE.sub.1 to UE.sub.X-1 within the network coverage. As a result, the bandwidth requirement

(34) $\underset{i=1}{\overset{X-1}{.Math.}}C\left(i\right)$
may be reduced to allow the external mobile device UE.sub.X to use the second network NW.sub.2 for data transmission (i.e. the sum of the adjusted

(35) $\underset{i=1}{\overset{X-1}{.Math.}}C\left(i\right)$
and C(x) may be smaller than the maximum bandwidth NWB.sub.2 of the second network NW.sub.2).

(36) The previous and current status of the adjustments to sum of the minimum bandwidth requirements of the mobile devices UE.sub.1 to UE.sub.X-1 within the network coverage may be recorded within the respective mobile device or be recorded in the resource management device RM. The recorded adjustments of bandwidths may include reduced (released) bandwidth scaling, bandwidth requirement scaling, etc. of the mobile devices UE.sub.1 to UE.sub.X-1. Therefore, when the external mobile device UE.sub.X needs to establish a data link with the first network NW.sub.1 and the second network NW.sub.2, the mobile devices UE.sub.1 to UE.sub.X-1 within the network coverage or the resource management device RM may adjust the respective sum of minimum bandwidth requirements according to the adjustments to sum of the minimum bandwidth requirements recorded within the mobile devices UE.sub.1 to UE.sub.X-1 or the resource management device RM such that the external mobile device UE.sub.X may be able to perform data transmission using the sum C(X) of the minimum bandwidth requirements. To promote reducing (releasing) of bandwidth by the mobile devices UE.sub.1 to UE.sub.X-1, behaviors for releasing bandwidths such as the scaling, bandwidth adjustment, etc. may be converted to a value of contribution of the system. When the mobile devices UE.sub.1 to UE.sub.X-1 re-establish a data link with the first network NW.sub.1 and the second network NW.sub.2 after disconnecting, the data transmission system 200 may perform compensation according to the value of contribution of the system of the mobile devices such that the mobile devices may be allocated with the optimal or minimum bandwidth priority.

(37) In another method, when the bandwidth usage for the first network NW.sub.1 and the second network NW.sub.2 is greater than a predetermined value, the data transmission system 200 may force the mobile devices UE.sub.1 to UE.sub.X-1 to terminate the application programs using maximum bandwidth requirement, such as video streaming programs, and allow the first network NW.sub.1 and the second network NW.sub.2 to accommodate more users.

(38) However, the abovementioned bandwidth adjustment method may be performed even when the external mobile device UE.sub.X has not been detected to want to link to the first network NW.sub.1. That is, the mobile devices UE.sub.1 to UE.sub.X-1 within the network coverage may directly adjust the bandwidths being used. For example, the mobile devices UE.sub.1 to UE.sub.X-1 may link to the first network NW.sub.1. Each of the mobile devices UE.sub.1 to UE.sub.X-1 may have at least one application program running. Therefore, each of the mobile devices UE.sub.1 to UE.sub.X-1 may use a bandwidth corresponding to a mobile device. When the data transmission system 200 acquires the sum of the bandwidths for each of the mobile devices and determines that a sum of the bandwidths of each of the mobile devices exceeds a predetermined value, the first network NW.sub.1 may broadcast a bandwidth limitation message to the mobile devices UE.sub.1 to UE.sub.X-1. After receiving the bandwidth limitation message, all or apart of the mobile devices UE.sub.1 to UE.sub.X-1 may use a bandwidth smaller than a predetermined limit so that each of the mobile devices UE.sub.1 to UE.sub.X-1 may have a sum of bandwidths smaller than or equal to the predetermined value.

(39) According to abovementioned embodiments for determining different bandwidth conditions and determination of said condition, the data transmission system 200 may be able to use a different bandwidth allocation strategy for the mobile devices UE.sub.1 to UE.sub.X. The present invention is not limited to the above described embodiment. In other embodiments, aside from using a different method of determining condition, the condition

(40) $\underset{i=1}{\overset{X}{.Math.}}C\left(i\right)>{\mathrm{NWB}}_1\mathrm{or}\underset{i=1}{\overset{X}{.Math.}}V\left(i\right)>{\mathrm{NWB}}_1$
may be changed to respectively

(41) $\underset{i=1}{\overset{X}{.Math.}}C\left(i\right)>{\mathrm{Th}}_1\mathrm{or}\underset{i=1}{\overset{X}{.Math.}}V\left(i\right)>{\mathrm{Th}}_2,$
wherein Th.sub.1 and Th.sub.2 are two predetermined values. The predetermined values Th.sub.1 and Th.sub.2 may or may not be identical. The use of the predetermined values Th.sub.1 and Th.sub.2 increases the flexibility of the data transmission system 200 to perform bandwidth allocation. Furthermore, as shown in FIG. 3, the mobile devices UE.sub.1 to UE.sub.X-1 within the network coverage may use the resource management device RM of the first network NW.sub.1 and the second network NW.sub.2 to send bandwidth feedbacks. The mobile devices UE.sub.1 to UE.sub.X-1 may send bandwidth feedbacks to the resource management device RM to register the bandwidth allocation. When the external mobile device UE.sub.X links to the first network NW.sub.1 and the second network NW.sub.2, the external mobile device UE.sub.X may send a bandwidth message and register a bandwidth allocation to the resource management device RM. The resource management device RM may then send a report including the bandwidth utilization status and the bandwidth allocation status of the external mobile device UE.sub.X to the mobile devices within the network coverage. And, the adjustment of the bandwidths for the mobile devices UE.sub.1 to UE.sub.X is managed according to the above described conditions.

(42) The present invention discloses a data transmission system that uses a plurality of heterogeneous networks for allocating the bandwidths used by application programs currently running. The resources (bandwidths) of the plurality of heterogeneous networks are used simultaneously. Therefore, as compared to the prior art that only uses a single network, the data transmission system of the present invention may not only increase the data transmission rate, but also optimize the bandwidth utilization efficiency of application programs currently running. In doing so, the user may be provided with a better linking quality when using a foreground application program.

(43) Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.