BRIEF DESCRIPTION OF THE DRAWINGS
The preferred embodiments of the present invention are shown by a way of example, and not limitation, in the accompanying figures, in which:
FIG. 1 is an architectural diagram showing an illustrative concept of dual functionality moving “networks information server;”
FIG. 2 is a flow diagram showing an illustrative method for how an MIS can be populated in some embodiments;
FIG. 3 is a flow diagram showing an illustrative method for how a database can be maintained in some embodiments; and
FIG. 4 is an architectural diagram showing illustrative computer or the like structure that can be used to implement computerized process steps, to be carried out by devices, such as, e.g., a server and/or a mobile device.
DISCUSSION OF THE PREFERRED EMBODIMENTS
While the present invention may be embodied in many different forms, a number of illustrative embodiments are described herein with the understanding that the present disclosure is to be considered as providing examples of the principles of the invention and that such examples are not intended to limit the invention to preferred embodiments described herein and/or illustrated herein.
Overview
Future Mobile Communication Systems will focus on integration of heterogeneous Radio Access Technologies. These technologies may comprise, e.g., PANs (Personal Area Networks with very small coverage), WLANs (Local Area Networks with comparatively large coverage area), and WANs (Wide Area Networks with comparatively larger coverage area e.g., cellular or WiMAX). Since focus is on integration, the requirements are more stringent than those for simply interworking. One such requirement is global roaming across these heterogeneous Radio Access Technologies with ubiquitous and transparent service provisioning. Global Roaming necessitates efficient method for quick vertical handovers, which in turn demands an efficient way of Heterogeneous Radio Access Networks Discovery. Several techniques have been proposed, however they have some drawbacks. We propose a new approach in this application that comprises a Moving Information Server (MIS). Such an Information Server can be installed, e.g., in vehicles, such as, e.g., trains, trams, buses, or any mass public transport system, etc., and can serve two purposes:
1: Acts as a Moving Information Server (MIS). In this regard, it can provide information ahead of time to, e.g., the Mobile Nodes (MNs) sitting in the vehicle (such as, e.g., passengers carrying an MN on a train, in a bus or the like) about the available networks in the geographical domain the vehicle is passing through or about to pass through. The Moving Networks Information Server (MIS) maintains the updated list of the Known Networks mapped with the location information. The MIS collects network information by receiving radio signals from the networks and or by actually connecting to the networks that fall on the track/route of the vehicle, and the Location Information through, e.g., a GPS Receiver. It is assumed that MIS in public vehicles can keep the updated information about the networks because it will pass through the same networks on the route it goes over periodically (e.g., several times a day). The MNs can receive network information from MIS through broadcasts, query-response, or combination of both. Preferably, the MIS is Multiple interface Device capable of delivering information on Multiple Radio Interface (e.g., IEEE 802.11, 802.16, 3GPP or 3GPP2). Preferably, the MN can pick the information through an interface it is currently using.
2: Act as a Reporting Agent. In it sends the copy of the same information (i.e. about the available networks mapped with GPS coordinates) to a Fixed Information Server (FIS) located somewhere in the Network. The FIS can serve those MNs which are not traveling in public vehicles and, thus, do not have access to MIS (e.g., pedestrians or travelers in private vehicles lacking a MIS). The communication channel between the MIS and the FIS may be either any appropriate Wireless Link or a Broadband Power Line (BPL).
Because the MIS installed in the vehicles is preferably capable of performing the above noted two functions at a time, we refer it to as Dual Functionality Moving Networks Information Server.
Introduction
Seamless integration of heterogeneous wireless networks is a major step towards a new generation of wireless networks. This seamless integration requires capabilities to support seamless handover to enable service continuity across heterogeneous Radio Access Technologies (RATs). The following are certain key capabilities to support seamless handover across heterogeneous RATs:
- Quick network discovery: To discover the existence of networks and information regarding the networks that a mobile station (MN or mobile for simplicity) will need to handover to.
- Down selection of candidate networks: When multiple networks are available at the same time, a MN needs to quickly select one network to use.
- Proactive handover: A MN may perform proactive handover actions before it actually hands over into a target network to reduce handover delay. For example, the MN may pre-acquire a local IP addresses from, and pre-authentication with, a target network.
The Known methods of “Networks Discovery” focus on two-stage approach.
Stage—1: Populating Information Server: Establishing an Information Server somewhere in the network, and filling it with the Networks Information by means of Reporting Agents (RAs). The RAs are regular MNs that collect the information about Network Elements in a domain they happen to visit and send it to the Information Server (e.g., if a specific network element is attached/detached or becomes operational/non-operational its information is reported to the Information Server by RA).
Stage—2: Reuse of Information Server's Information: Reuse of Information Server's information by new mobile entrants in that domain—i.e., any MN when it enters in a new domain can inquire to the Information Server about the Network Elements in that domain and get information in advance about Network Elements of any domain.
Drawbacks in the Background
There are drawbacks in both above noted stages. In Stage—1 (i.e., Populating Information Server) each and every MN that happens to enter in a domain, unaware of the fact that the previously present or passing-by MNs have already updated the Information Server, keeps on sending/replicating the same information about the domain it is passing through. This not only unnecessarily keeps the Information Server busy in processing the replicated information but also generates signaling burdens on the network gratuitously. Furthermore, since Reporting Agents are regular subscribers, they may not be trusted RAs.
In Stage—2 (Reuse of Information Server's Information), the prior methods assume that the MN is aware of Information server's reachable location. This method may not work well or may be inefficient if the MN is not aware of the Information Server's reachable locations, thus, bringing-in an unnecessary time delay.
Our proposed solution, in addition to the above noted issues (that are mainly related to the construction of database and its use), can also solve the problems posed by “Simultaneous Gang Handovers”—i.e., when a large number of MNs (e.g., in the train) move together, a large number of simultaneous handovers can occur. If the radio access network could get the knowledge ahead of time about this joint gang handover, it can better manage its available resources.
Furthermore, our proposed solution can also resolve the problems faced by “Moving Networks.” See Reference [1]. A Moving Network is a network which changes, as a unit, its point of attachment to the Network. To reduce the latency for promoting efficient session continuity for moving networks, the NEMO working group in IETF is proposing Mobile Routers. However, route optimization is a major concern. Several solutions have been proposed, among which establishing bi-directional tunnels seems the promising one. However, they have drawbacks of their own nature. For example, in the case of establishing a bidirectional tunnel, all communications to and from nodes in a mobile network must go through the bi-directional tunnel established between the Mobile Router and its Home Agent when the mobile network is away. Although such an arrangement allows Mobile Network Nodes to reach and be reached by any node on the Internet, the limitations associated to the base protocol degrade overall performance as it adds new delays (because of increased packet size, increased chance of packet fragmentation, and increased susceptibility to link failure, etc.) that eventually introduce bottleneck traffic congestion. The problem is further compounded by nesting of Mobile Networks that can ultimately stalemate all communications to and from the Mobile Network Nodes in specific dispositions. Our proposed idea of an MIS can be an alternative to Mobile Routers to achieve the objective. Where MIS does not provide the routing, but assists and guides MN to connect to the available networks that happen to fall on its way, in a quick, efficient and timely manner.
The Approach of the Preferred Embodiments
This application describes a new method, which not only can overcome the above captioned flaws and other flaws of the prior art but also provides a number of advantages, such as, e.g., listed below. According to some embodiments of present approach, as portrayed in FIG. 1, the Dual Functionality Moving Networks-Information-Server plays the roles of an MIS and a Reporting Agent and, preferably, has following functionalities.
With reference to FIG. 1, the figure depicts an illustrative embodiment of a dual functionality moving “networks information server” (DFM-NIS). As shown in FIG. 1, a vehicle 10 (e.g., a train as shown), includes a Moving Network Information Server (MIS) 20. As illustrated in FIG. 1, the vehicle 10 preferably has a plurality of passengers therein, such as, e.g., passengers P1 and P2 shown in the illustrative example. Moreover, the passengers preferably have a plurality of mobile devices or mobile nodes (MN) 30 (e.g., a personal computer, laptop computer and/or the like). In this illustrative embodiment, the train is powered via a broadband power line 40 (e.g., electrical power line). Moreover, in this illustrative embodiment the train communicates with a plurality of fixed Network Information Servers 50 (two shown in the illustrative embodiment). As also shown, the MIS can communicate in some embodiments with a FNIS via a wireless transmission system. As shown in FIG. 1, the MIS preferably operates as a dual functionality Moving Network Information Server in which it 1) acts as an Information Server for passengers and 2) acts as a reporting agent for a fixed Network Information Server (NIS).
1. Functionalities of Moving Information Server as MIS and Reporting Agent:
In the preferred embodiments, the MIS is made capable of performing at least some and preferably all of the following functions:
- 1. MIS is Capable of: Listening to the information received through Broadcasts and or Beckons from Cellular Networks (3GPP, 3GPP2, etc.) and from Non-Cellular networks (e.g., WLANs, WiMAX, PANs, etc.). The MIS collects this information by receiving radio signals from the networks and/or by actually connecting to the networks that fall on the track/route of the vehicle. In some preferred embodiments, this can be done as per the algorithm shown in FIG. 2. It is assumed that an MIS in, e.g., a public vehicle can keep the updated information about the networks because it will, e.g., traverse the same or similar route periodically (e.g., several times a day).
- With reference to FIG. 2, the figure shows an illustrative flow diagram depicting process steps for how an MIS database can be populated according to some illustrative embodiments. In this regard, in the illustrative example, at a first step 10, the process is started. Next, at step 20, the system receives GPS coordinates from a GPS receiver. Next, at step 30, the system listens to SSIDs and picks one. Next, at step 40, the system evaluates if an SSID belongs to a Legacy Type Format. If the answer at step 40 is no, the system proceeds to step 45 and sends a probe and gets the SSID and then proceeds to step 50. If the answer is yes at step 40, the system proceeds to step 50. At step 50, the system evaluates if it is already in the database. If the answer is yes at step 50, the system process back to step 30. If the answer is no at step 50, the system proceeds to step 60. At step 60, the system evaluates if the SSID belongs to HPLMN. If the answer is yes at step 60, the system proceeds to step 110 and stores the SSID and retrieved parameters in Category A of a Table-1, after mapping with LAI and CGI. If the answer is no at step 60, the system proceeds to step 70 and evaluates if the SSID belongs to HPLMN's Roaming Partners. If the answer is yes at step 70, the system goes to step 120 and stores the SSID and retrieved parameters in Category B of a Table-1, after mapping with LAI and CGI. If the answer is no at step 70, the system proceeds to step 80 and gets feedback from the mobile node (MN), and goes to step 90 optionally and stores/prioritizes the database information in the light of Customer's Feedback, and goes to step 100 and sends a probe and gets an SSID. Also, if the answer is no, the system goes to step 130 and stores the SSID and retrieved parameters in Category C of Table-1, after mapping with LAI and CGI and goes to step 20 and gets GPS coordinates from GPS receiver.
- 2. MIS is Capable of: Comparing the information (between the messages received recently and already stored information) and comprehending the inconsistencies as per, e.g., the algorithm shown in FIG. 3.
- 3. MIS is Capable of: Storing the Updated Information in its database. The MIS maintains the updated list of the Known Networks mapped with the location Information. MIS will be capable of Storing Information about Network Element Categorically duly Mapped with Geographical Location Coordinates and Time. In the preferred embodiments, there are three categories of stored information: “Primary Information;” Secondary Information; and 3rd Party Information. Primary Information can include, for example, SSIDs of available networks, addresses of a DHCP server, an address of an authentication server, etc. Secondary Information can include network capabilities and can be considered as the additional information that can include higher layer information or detailed information about lower layers. For example, Type of Security Protocols supported (e.g., Open Access Control; Universal Access Control; or 802.1X Access Control), Type of Internet Protocols supported (e.g., IPv4, IPv6, etc.). Support for Quality of Service (QoS), Support for interworking with other networks, Existence of Roaming Relationship and Names of Roaming Partners, Pricing Information, and Services Supported by the networks. These two categories of information will help the MN to determine the candidate networks and perform pre-authentication with the best one ahead of time. The 3rd Party Information can be, e.g., location based Information provided to the interested MNs that otherwise the MN has to acquire from a Location Server, located at the far end of the network, at the expense of extra signaling and battery consumption. The significance of categorizing the information in Primary, Secondary and 3rd Party is that some of the Information may be Broadcasted (e.g., Primary Information can be broadcasted) and some of the information can be acquired on query response basis (e.g. Secondary Information, or 3rd Party Information can be fetched based on need). Preferably, the database is maintained as per, e.g., the algorithm shown in FIG. 3.
- With references to FIG. 3, FIG. 3 shows an illustrative flow diagram for how a database is preferably maintained according to some illustrative embodiments. In this illustrative example, the database includes three databases—i.e., a 3rd party information database 320, a networks capabilities and performance database 330 and a networks parameters database 250. As shown, at step 200, the system is started. Next, at step 210, the system listens to broadcasts/beckons and gets network information from received radio signals. Next, at step 220, the system gets GPS coordinates. Next, at step 230, the system checks local memory (e.g., is the network mapped at X1, Y1, Z1 available?). If the answer is no at step 230, the system goes to step 240 and updates the database with received information. If the answer is yes at step 230, the system goes to step 260 and evaluates to compare memory with the received parameter-change observed. If the answer is no at step 260, the system proceeds to step 290 and increases a stability index and next proceeds to step 310 and updates the Networks Performance Database. If the answer is yes at step 260, the system proceeds to step 300. Also, if the answer is yes at step 260, the system proceeds to optional step 270 and receives feedback pertaining to Network Performance from Users currently using this network. Next, at step 280, the system evaluates if the feedback pertaining to performance from the Users is good. If the answer is at step 280 is no/no feedback, the system goes to step 300 and decreases the stability index and next proceeds to step 310 and updates the Networks Performance Database. If the answer at step 280 is yes, the system proceeds to step 290 and increases the stability index, and next proceeds to step 310 and updates the Networks Performance Database.
- 4. MIS is Capable of: Providing information to the Mobile Nodes sifting in the vehicles, ahead of time, about the available networks in the geographical domain the vehicle is passing through or about to pass through.
- 5. MIS is Capable of: Delivering MNs the network information through broadcast, or query-response, or combination of both. The MIS is a Multiple Interface Device and is capable of providing information to the MN through, e.g., a radio interface the MN is currently using (e.g., IEEE 802.11, 802.16, 3GPP or 3GPP2).
- 6. MIS is Capable of: Pushing or notifying the information to the FIS, thus updating the FIS database accordingly, in this manner, it also acts as a reporting agent for the FIS.
- 7. MIS is capable of: Sending ONLY Updated Information to the FIS either on Broadband Power Line (BPL) or any appropriate Wireless Interface (in case BPL for backhaul connection is not available). In this regard, the BPL is used to deliver IP-based broadband services on electric power lines. The FCC is trying to create competition with, e.g., copper telephone lines and cable television coaxial cable lines.
- 8. MIS is capable of: Informing the FIS to take an appropriate action to handle simultaneous gang handovers that may result due to the mobility of several MNs in a moving vehicle with active calls. FIS in turn may inform the appropriate base station to manage its radio resources accordingly.
2. Functionalities of the Fixed Information Server:
The MIS and the FIS are both Information Servers. One difference is that the MIS is a Moving Information Server, and the FIS is a Fixed Information Server. Moreover, the FIS has comparatively less functionalities. In some embodiments, the FIS is capable of performing at least some and preferably all of the following tasks:
- 1. FIS will be capable of Receiving ONLY Updated Information about Network Elements of domains through different MIS.
- 2. FIS will be capable of Storing Information (e.g., a duplicate copy of Information that MIS has provided to it).
- 3. FIS will also be capable of delivering Primary, Secondary, or 3rd Party Information to the MNs, through MN inquiries only.
- 4. FIS, on default, is a recipient of duplicate copy of Information that the MIS provides to it. However, it has a special feature under which it can supply and/or overwrite the information contained in MIS. This information can be, e.g., operator's policy driven or 3rd party information. Thus, for example, advertisements, etc., can come from the FIS to the MIS for further delivery to the MNs.
- 5. FIS is capable of informing appropriate Base station/Access Point to manage radio resources to handle a simultaneous gang handover that may result due to the mobility of an entire Network with active calls.
3. Functionalities of MNs:
According to some embodiments of this approach, the Mobile Nodes are made capable of performing at least some, preferably all, of the following functions:
- 1. The MNs are capable of listening to the Broadcasts from the MIS to get Primary Information about Network Elements. In another embodiment of the present invention, for charging purposes (e.g., fees), the broadcasts can be IP packets that are addressed to those MNs who are subscribed customers.
- 2. The MNs are capable of obtaining Secondary or Additional Information about Network Elements by sending a direct query to the MIS. The partition between the Primary and Secondary Information is policy/implementation based. Both the Primary and Secondary Information received through Broadcasts from and through query to the MIS, respectively, will help the MN to, e.g., determine the available candidate networks, down select the best candidate as per its own policy and preferences, and perform pre-authentication with the best one ahead of time. In the preferred embodiments, the 3rd Party Information is not used for Network Discovery, but to provide supplementary services.
Once the MN has selected the best network, it can initiate essential steps to perform proactive secured handoff (e.g., sending PANA authentication message to the PANA server, renewal of IP address with DHCP server of the candidate network, and sending a binding update to the correspondent host (CH) or to the home agent).
4. Merits of the Proposed Solution
This approach will not only surmount the flaws present in the existing techniques but also provides a number of potential advantages, including, e.g.;
- 1. It can solve discovery database construction problems because, e.g., it constructs a database in an automated, dynamic and efficient way. Furthermore, network discovery and updated reports, being constructed in the MIS and reported by the MIS to the FIS will be trusted—i.e., in contrast to when regular MNs are acting as reporting agents.
- 2. Since the MIS is made capable of sending only the updated information, this can eliminate the redundant signaling traffic as well as relieve the FIS from unnecessary processing of replicated information. In contrast, in existing techniques all Reporting Agents whenever and wherever they find any network just keep on sending the information to the Networks Data Server, which increases signaling traffic on the Network and processing burdens on the FIS.
- 3. The MIS can provide the MNs with quick and reliable information about the neighborhood networks. It can do this because; (a) the MIS can keep updated information about the networks—for example, when used in a vehicle, such as, e.g., a public vehicle (e.g., a public transportation vehicle in some illustrative embodiments), it will traverse the same route periodically (e.g., several times a day); and (b) the MIS is local and relatively stationary with respect to the MN.
- 4. The superfluous signaling traffic on the network will be reduced. This can be achieved because every MN will be able to get the desired information about heterogeneous networks from the Local MIS.
- 5. Regardless which interface of a MN is active, the MN will be able to retrieve the desired information from the MIS because the MIS is a multiple air interface Server capable of sending information on several heterogeneous air interfaces.
- 6. The proposed approach will be able to reduce the battery consumption for the MN. This can be achieved because, e.g., it can fetch the desired information locally, and using an air interface that is already active.
- 7. Since the MIS can also provide location based information, this can relinquish the MNs from keeping their own global position systems (GPS) ON, thus offering power saving to the MNs. Furthermore, if can also reduce location based data and signaling traffic on the network. This is desirable for both users and network service providers.
- 8. The MIS can also store and deliver 3rd parties information to the MNs. This will create a Business case for e.g., advertisers and network operators. In addition, it can make a business case for railway companies, or mass transport companies, as they can assist network operators to provide guaranteed service to the users even if the users utilize heterogeneous networks. It can also make business case for 3rd parties who might be interested in providing location based advertisements or information services.
- 9. The MIS can inform the radio access network ahead of time about a simultaneous gang handover, thus enabling it to manage its available resources in a timely manner. This is a very desirable benefit/feature for, e.g., network operators.
- 10. It can be an alternative solution to the Mobile Routers concept. The concept of Mobile Router for Moving Networks is being pursued by the NEMO working group of the IETF with an objective to reduce latency. In our proposed idea, the MIS does not provide the routing to the moving network, but assists and guides the MNs of a moving network to connect the available networks on their way in quick, efficient and timely manner, thus reducing the latency and delays, which is also the key objective of NEMO. Notably, in the context of Moving Networks, Mobile Routers and Gateways to the outer world have to be automatically discovered and re-established after departure/failure of a gateway; however, the MIS can also serve as a discoverer of Mobile Routers and Gateways in advance to assure continuous reachability.
BROAD SCOPE OF THE INVENTION
While illustrative embodiments of the invention have been described herein, the present invention is not limited to the various preferred embodiments described herein, but includes any and all embodiments having equivalent elements, modifications, omissions, combinations (e.g., of aspects across various embodiments), adaptations and/or alterations as would be appreciated by those in the art based on the present disclosure. The limitations in the claims (e.g., including that to be later added) are to be interpreted broadly based on the language employed in the claims and not limited to examples described in the present specification or during the prosecution of the application, which examples are to be construed as non-exclusive. For example, in the present disclosure, the term “preferably” is non-exclusive and means “preferably, but not limited to.” In this disclosure and during the prosecution of this application, means-plus-function or step-plus-function limitations will only be employed where for a specific claim limitation all of the following conditions are present in that limitation: a) “means for” or “step for” is expressly recited; b) a corresponding function is expressly recited; and c) structure, material or acts that support that structure are not recited. In this disclosure and during the prosecution of this application, the terminology “present invention” or “invention” may be used as a reference to one or more aspect within the present disclosure. The language present invention or invention should not be improperly interpreted as an identification of criticality, should not be improperly interpreted as applying across all aspects or embodiments (i.e., it should be understood that the present invention has a number of aspects and embodiments), and should not be improperly interpreted as limiting the scope of the application or claims. In this disclosure and during the prosecution of this application, the terminology “embodiment” can be used to describe any aspect, feature, process or step, any combination thereof, and/or any portion thereof, etc. In some examples, various embodiments may include overlapping features. In this disclosure, the following abbreviated terminology may be employed: “e.g.” which means “for example.”
Patent Application
20080056210
