JP2004537195A - Seamless communication system and method via optimal network - Google Patents

Abstract

A communication system for communicating over the Internet, comprising a portable communication device and a plurality of networks interconnecting the Internet with the portable communication device at least from time to time. The Internet is also interconnected with intelligent content servers. A network management component is interconnected with the intelligent content server and selects which network to use for communication between the intelligent content server and the portable communication device.

Description

【Technical field】
[0001]
The present invention relates generally to mobile communication platforms, and more particularly to communication optimization using intelligent network selection.
[Background Art]
[0002]
Cellular or personal handyphone system (PHS) telephone devices are configured to communicate with a plurality of terrestrial-based or satellite-based antennas, which are ultimately connected to a conventional telephone system. Regardless of the particular path used, there is a direct link between the cellular telephone and the telephone system communication network. Digital cellular telephone devices are also capable of sending and receiving digital data to and from a digital data network to which the telephone system is interconnected, such as the Internet. Such devices have been referred to as personal communication system (PCS) devices. Such enhanced personal communication system (PCS) devices request information from the Internet, such as maps, e-mails, text, web pages, audio (audio) and video (video) files. , Can be received and displayed.
[0003]
One of the problems associated with such enhanced features is the bandwidth required to transmit large amounts of data. Many existing data communication networks have problems with scheduling and routing of data transmission, and with inefficient allocation of data transmission capacity. For example, the global interconnection of computer networks known as the Internet routes data packets in the expectation that they will ultimately be transmitted to their intended recipients, while the packets are transmitted during transmission. Loss or delay is not uncommon. Further, the Internet does not distinguish between the various types of data being transmitted.
[0004]
Data packets that need to be transmitted within a fixed time frame, such as real-time (real-time) audio and video communications, are given priority over packets that generally do not require a specific transmission time, such as e-mail. It will not be done. Data packets that carry important information, such as medical images, for which packet loss is not tolerated, do not take precedence over other data packets. Since all data packets are considered equally important in terms of transmission resource allocation, do less important transmissions, such as e-mail, delay data that is more important and time sensitive? May work to push away.
[0005]
The capacity of data transmission in existing data communication networks is often allocated inefficiently. In some cases, even if the transmission capacity or bandwidth is allocated to a particular user according to a fixed schedule or a particular network architecture, this available bandwidth is not actually used. Also, in some cases, the user may not be able to transmit data bursts that temporarily exceed the user's bandwidth allocation. Existing data communication networks often lack mechanisms that allow bandwidth to be allocated on demand.
[0006]
Current cellular telephone systems use relatively low bandwidth communication technologies of about 50 kilobits per second. For graphical (image) information such as maps and images, a relatively large bandwidth is required to achieve a reasonable response time. For video and audio files, more bandwidth is needed for proper response time. With limited spectrum resources, bandwidth costs on relatively narrowband networks can be expensive.
[0007]
Current television signal broadcasting systems provide relatively wide bandwidth capabilities of about 20 megabits per second for each 6 megahertz wide television channel. The terrestrial frequency band in the United States includes approximately 400 megahertz of available spectrum. Terrestrial broadcast channels typically have a coverage radius of about 70 miles (about 112.651 kilometers), which is highly dependent on local terrain.
[0008]
Also, direct digital satellite television broadcast systems can provide digital channels that can be used for digital information transmission. An example of such a system is "PRIORITY BASED BANDWIDTH," issued April 2, 2002 to Montpettit, "Priority-Based Bandwidth Allocation and On-Demand Bandwidth in Orbiting Satellite Data Communications Networks." ALLOCATION AND BANDWIDTH ON DEMAND IN A LOW EARTH ORBIT SATELLITE DATA COMMUNICATIONS NETWORK), which is disclosed in U.S. Patent No. 6,366,761. Digital data from these channels can be received over a much larger area, typically including tens of thousands of square miles. These channels are not yet fully used. Thus, there is a large amount of unused television broadcast spectrum available for other uses.
[0009]
Some data requested by a user of a personal communication system (PCS) device is specific to that user, such as an email addressed only to that user. Other data is of interest to many users at the same time, such as weather data and stock market quotes. Other information is of widespread interest only at certain times, such as the tax return of the National Tax Service in the second week of April. The Internet and associated IP protocols would be expected to meet the increasing demand for data. The network can be connected to a broadband modem (cable, DSL, or satellite) via wired or wireless means, to a nomadic network provided by a wireless LAN standard system, or to a mobile network. It can be set by various means, including connecting to the body network. Current bandwidth for cellular telephone devices is almost inadequate to provide such information when specific information is required for a particular personal communications system (PCS) device, and all available If this bandwidth does not end up being used up by increasing users, then one must find a more efficient way to access the appropriate network for the bandwidth actually needed.
[0010]
Within a single network, the mechanisms or protocols required to connect to this network in order to obtain a range of services are simple problems whose solutions are known. However, the problem of performing seamless transitions when different networks must be traversed is important. For example, in second generation cellular networks, it is often possible to connect to a different network for each session.
[0011]
Unfortunately, the mechanisms for communicating between networks do not have the potential to optimize bandwidth at the packet level because there is no common protocol layer. On the Internet, a commonly used protocol is called IPv4, which has a set of tools that allow it to manage mobility. The set of these protocols is called the Mobile IP protocol. Several enhancements to the IPv4 protocol have resulted in a second generation called IPv6. In addition to the extended address space of 128 bits instead of 32 bits used in IPv4, there are several features that allow for better mobility management. In IPv6, mobility can be managed using a static IP addressing scheme. In IPv4, dynamic and local IP address assignment is often used due to lack of address space. With IPv6, the efficiency of address management is expected to be better, resulting in better overall services. An example of a mobile system using IPv6 is the United States entitled "Mobile Node, Mobile Agent and Network System (MOBILE NODE, MOBILE AGENT AND NETWORK SYSTEM)," issued Jan. 9, 2001 to Mr. Watanuki. It is disclosed in Patent No. 6,172,986.
[0012]
Data requested by a user has a property that time is critical (critical), and may need to be transmitted under strict time constraints. Alternatively, data may be downloaded under less stringent time constraints. In the former case, a quality of service (QoS) constraint that the network needs to support is required. The latter is the normal download model for Internet content and is referred to as best effort (best effort) transmission. Finally, data may be transmitted with a time delay. Examples include music or multimedia that the user wants to watch later. This category represents the highest flexibility that comes from a network optimization and usage perspective.
DISCLOSURE OF THE INVENTION
[0013]
As mentioned briefly above, when there are many networks, bandwidths and accessibility variables, the required bandwidth and message priority so that the lowest cost and minimum required bandwidth is always selected There is a need for a mechanism that allows users to seamlessly roam or transition between these networks based on calculations of bandwidth and bandwidth costs.
[0014]
In accordance with the principles of the present invention, a communication system for communicating over the Internet includes a portable communication device and a plurality of networks that at least occasionally interconnect the Internet with the portable communication device. The Internet is also interconnected with intelligent content servers. A network management entity is interconnected with the intelligent content server and selects which network to use for communication between the intelligent content server and the portable communication device.
[0015]
In such communication systems, the problem of optimizing network selection by selecting the most cost-effective available bandwidth implements a portable communication device as a portable intelligent multiple network platform. Is dealt with. The platform includes a plurality of front-end interfaces, each interface being of a certain type, such as a home (home) network interface, a broadcast network interface, a hotspot type nomadic network interface, or a mobile network interface. Corresponds to available networks. The home network interface is typically plugged into a broadband modem, while other interfaces utilize antenna terminals to perform wireless communication.
[0016]
Within the platform, each network interface is interconnected with a network data processing layer that can send and receive data via either IPv4 or IPv6 protocols. For large files that require significant bandwidth, such as multimedia applications, the network data processing layer is interconnected to separate back-end application processing devices that process and buffer the data stream.
[0017]
Each network interface sends and receives data to and from a base station or network termination dedicated to that particular type of network. Each such base station or network termination has a suitable connection to the Internet. Also connected to the Internet is an intelligent content server interconnected with network management components. To allow the intelligent content server to communicate with the portable intelligent multiple network platform, the platform registers with any of the available networks via any physical layer with a return channel. .
[0018]
The platform can work with existing mobile IPv4 protocols or use a static IPv6 global addressing scheme. The platform communicates with the intelligent content server and informs the server of the current IP address and current specific multi-networking capabilities. The intelligent network management component selects the appropriate network to use for each packet transmitted or received based on optimization criteria such as priority, desired transmission quality, required bandwidth, cost, and the like.
[0019]
When the portable platform leaves the current network in which it is operating (generally because it physically moves beyond the scope of the current network), it becomes the next best Automatically search for (based on optimization criteria) and attempt to connect to it. When a new connection is successfully completed, the portable platform sends information about the current connection to the network management component. In response to this information, the intelligent network management component routes subsequent packets through this newer optimal network path. This process can be managed on a per-packet or per-session level.
BEST MODE FOR CARRYING OUT THE INVENTION
[0020]
FIG. 1 is a block diagram of a mobile communication system including a multiple network portable platform 10. The multi-network portable platform 10 is capable of bi-directional transmission and reception with the broadband modem 12 or any of a plurality of wireless communication networks via antennas 122, 126, 128. In practice, antennas 122, 126, 128 may be a single physical antenna with a suitable matching network, or may be one or more physically close antennas. For example, antenna 122 is responsive to digital cellular telephone signals from a cellular telephone mobile network terminal or base station 22. The antenna 122 is bidirectionally coupled to the mobile interface circuit 120.
[0021]
As can be seen in FIG. 2, the mobile interface circuit 120 is coupled to a direct data input terminal of the microprocessor 118. A direct data output terminal of the microprocessor (μP) 118 is coupled to an input terminal of the mobile interface 120. An audio output terminal of the microprocessor 118 is coupled to an input terminal of the speaker 114. An output terminal of the microphone 112 is coupled to an audio input terminal of the microprocessor 118. An output terminal of keypad 116 is coupled to a control input terminal of microprocessor 118.
[0022]
Microprocessor 118 operates in a well-known manner under the control of application programs stored in a memory such as a read only memory (ROM) in microprocessor 118. Specifically, the microprocessor 118 utilizes both the current Internet Protocol version 4 (IPv4) and the still-evolving next-generation Internet Protocol version 6 (IPv6) to implement the data processing layer 130. It is programmed to work as Layer 130 may include a quality of service (QoS) program, as is well known to those skilled in the art.
[0023]
The microprocessor 118 also includes a back-end application processor 14 capable of bidirectional communication with the Internet protocol layer 130. Processing unit 14 serves as a buffer and decoder for data received by microprocessor 118, and is particularly useful for processing data having multimedia content, such as audio and video files. The back-end application processing unit 14 can be a circuit composed of discrete components, or an integrated circuit (IC) external to the microprocessor 118 but also implemented on the multiple network portable platform 10. May be combined.
[0024]
Platform 10 operates in a well-known manner, as described above, to allow a user to place a call. The user operates the keys on keypad 116 to instruct microprocessor 118 to connect mobile interface circuit 120 via mobile base station 22 to an external network, such as the Internet 30 or a cellular communication network. I do. The keypad 116 generates a dial tone specifying a desired telephone number or command code. Alternatively, a signal may be received from the Internet 30 or a cellular telephone network indicating that someone is about to call the portable platform 10. In response to these signals, microprocessor 118 controls mobile interface circuit 120 to connect to the network and complete the call.
[0025]
In either case, a signal representing call information from microphone 112 is digitized by microprocessor 118 and the digitized signal is transmitted to mobile network base station 22 via mobile interface 120 and antenna 122. You. At the same time, a signal, which is received from the base station 22 by the antenna 122 and represents the received digitized call information from the other party, is received by the mobile interface 120, converted to a voice signal by the microprocessor 118, and transmitted to the speaker 114. Supplied.
[0026]
As described above, generally, the multiple network platform 10 also has a function of requesting and receiving information from a computer via the Internet. Data representing the required information can be generated by the user from the keypad 116. The keypad 116 may have more keys than shown in FIG. The information request is provided from microprocessor 118 to any of the network interfaces available on network platform 10. For example, the platform 10 may include not only a mobile interface 120 but also a home network interface 110, a nomadic network interface 16, and a broadcast network interface 18. Depending on which network is available, the information request is forwarded to the broadband modem 12 or to one of the antennas 122, 126, 128.
[0027]
Regardless of the network being used at any particular time, the information request is sent to the Internet 30. From the common layer 130, a status report is also provided as to which of the network interfaces 16, 18, 110, 120 is currently communicating with its associated network. Each of these networks has unique characteristics associated with that particular network path. These characteristics include the bandwidth of the network path, the monetary cost of using the network, the available data rates, the quality and reliability of the network, the geographic reach of the network, and the transmission over that particular network path. Data types that are best suited for By transmitting the current range of network availability, the receiver can select the best network to transmit the reply data.
[0028]
Information transmitted from the platform 10 to the Internet 30 is received by a server machine, such as an intelligent content server 27, containing information desired by the user of the portable platform 10. A network management component 26 is interconnected to the content server 27 and receives network availability or status reports from the platform 10. The management component 26 is programmed to optimize the selection of the network through which the associated content server 27 will send and receive data to and from the platform 10.
[0029]
There are two possible modes for transmitting desired information from the server 27. The first mode is a unicast (single communication) mode, in which server data is directed only to a specific user platform 10. A second possible mode is a multicast mode, in which server data is intended to be transmitted to multiple platforms 10 simultaneously.
[0030]
In either case, the purpose of the server 27 is to route data to the "edge" 31 of the global computer network via the backbone or internal structure of the Internet 30 and to select from the edge 31 Transporting P packets to the platform 10 by continuing to transmit data to the platform 10 via the communication access networks 20, 21, 22, and / or 25.
[0031]
The purpose of the unicast mode is to minimize the following equation so that the network management component 26 can optimize the selection of a particular network from the range of available networks. I do.
(Equation 1)
In the above formula,
x _i is the cost of transporting each data packet to its edge 31 via the Internet 30 toward the i-th access line.
y _i is the cost of carrying each packet over the respective access network, eg, 20, 21, 22, 25.
P _j is the number of packets carried on link i.
_Ni is the number of users on the i-th link requesting the contents of the server 27.
[0032]
This unicast equation can be solved as an optimization problem using standard optimization techniques, so that the entire network, ie, the Internet 30 and subsequent communication networks 20, 21, 22, or 25, The cost of transporting each packet over the network will be reduced. To enable service quality, the cost structure for each of the previously used segments x _i and y _i is appropriately reflected, and the optimization problem is solved with new numbers.
[0033]
In the case of multicast, the aim is to minimize the following equation:
(Equation 2)
[0034]
This equation is identical to the unicast mode, except that the penalty incurred for multiple users (N _i ) requesting server content is removed. This equation can also be optimized using well-known optimization techniques. Each optimization can be performed on a packet-by-packet or session-by-session basis.
[Brief description of the drawings]
[0035]
FIG. 1 is a block diagram illustrating a selection and optimization system for a portable communication network according to the principles of the present invention.
FIG. 2 is a block diagram of a personal communication system device according to the principles of the present invention that can be used in the system shown in FIG.

Claims (20)

A communication system for communicating via the Internet,
A portable communication device,
A plurality of networks, each interconnecting the Internet with the portable communication device at least occasionally;
An intelligent content server interconnected with the Internet;
A network management component interconnected with said intelligent content server, said network management component selecting which network to use for communication between said intelligent content server and said portable communication device A communication system comprising: The communication system of claim 1, wherein the portable communication device comprises a plurality of network interfaces for establishing a communication link with each of the plurality of networks. The communication system according to claim 2, wherein the portable communication device further comprises a microprocessor programmed to process data via any of the network interfaces. 4. The communication system of claim 3, wherein the network management component is programmed to select a network to be used for communication with the portable communication device based on available bandwidth of each of the plurality of networks. . 5. The communication system of claim 4, wherein the network management component evaluates costs associated with each network in selecting networks to use for communication with the portable communication device. The communication system according to claim 5, wherein the network management component evaluates transmission quality values associated with each network when selecting networks to be used for communication with the portable communication device. The network management component evaluates a network used to communicate with the portable communication device for each data packet transmitted between the intelligent content server and the portable communication device. 7. The communication system according to 6. 7. The communication system of claim 6, wherein the network management component evaluates a network used to communicate with the portable communication device for each data transmission session. 9. The communication system of claim 8, wherein the microprocessor is programmed to transmit all information between each network interface using a common Internet Protocol layer. The microprocessor,
Determining which of the plurality of networks is operating;
The communication system of claim 9, wherein the communication system is programmed to send information indicating which of the plurality of networks is operating to the network management component. A data transmission optimization system for use in a multi-network environment,
An intelligent content source (27);
An intelligent network management component (26) interconnected with said intelligent content source;
A plurality of network platforms interconnected to a plurality of communication networks, said plurality of network platforms transmitting a communication network status report to said intelligent network management component, said intelligent network management component comprising: Selecting a communication network (20, 21, 22, 25) for transmitting data from said intelligent content source to said plurality of network platforms. The data transmission optimization system of claim 11, wherein the intelligent network management component selects one of the communication networks based on an optimization algorithm that includes network bandwidth as a variable. The data transmission optimization system according to claim 11, wherein the optimization algorithm evaluates a data transmission cost of a network as a variable. The data transmission optimization system according to claim 11, wherein the optimization algorithm evaluates data transmission quality of a network as a variable. 12. The data transmission optimization system of claim 11, wherein the intelligent network management component selects one of the communication networks for each data transmission session with the multiple network platforms. 12. The data transmission optimization system of claim 11, wherein the intelligent network management component selects one of the communication networks for each data packet sent to the multiple network platforms. A method for optimizing data transmission between a portable platform and an intelligent content server by optimizing the choice of communication network in a multi-network environment, comprising:
Determining which communication network is connected to the portable platform;
Sending a communication network status report to the intelligent content server;
Causing a network management component to evaluate characteristics of the communication network connected to the portable platform;
Causing the network management component to select a communication network based on the evaluated characteristics;
Transmitting data from the intelligent content server to the portable platform via the selected communication network. The method of claim 17, further comprising evaluating a characteristic of the communication network for each data transmission session. The method of claim 17, further comprising evaluating a characteristic of the communication network for each data packet transmitted. 18. The method of claim 17, wherein data is transmitted from the intelligent content server to the portable platform via a common internet protocol layer.