Abstract:
Methods and systems for routing information to a destination through a plurality of networks, wherein at least one of the networks is a packet network. The system comprises a routing processor for receiving a routing query signal, which specifies the destination to which the information will be routed and a memory for storing at least one characteristic of the destination. The processor determines a route for the transmission of the information based on the routing query and on the characteristics stored in the memory.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates generally to the field of managing the routing of packets over a hybrid communication network, operating both in circuit switched and packet switched modes, and, more particularly, to the methods and systems for managing the routing of packets through the hybrid network based on the destination telephone number.  
         BACKGROUND OF THE INVENTION  
         [0002]    Traditional telephone service providers have been planning the transition to packet switched networks. In planning this transition, consideration must be given to providing POTS users, who only have analog equipment, access to such networks. Such a transition should also facilitate communication between fixed wireless subscribers and POTs subscribers. Additionally, consideration must be given to providing local subscribers with direct access to their packet network.  
           [0003]    Therefore, there remains a need to provide POTs and wireless service subscribers with improved direct access to packet networks, and particularly, a need for improving communication between such subscribers.  
         SUMMARY OF THE INVENTION  
         [0004]    The present invention overcomes the above, and other, limitations by providing communication methods and systems for routing packets, such as digitized voice, from a fixed wireless service subscriber to a destination over a hybrid network, operating in both circuit switched and packet switched modes.  
           [0005]    In one aspect, the invention features a system for managing the routing of information from a source to a destination through a plurality of networks, wherein at least one of the networks is a packet network. The system comprises a routing processor for receiving a routing query signal from the source. The signal specifying the destination to which the information will be routed. The system also comprises a memory for storing at least one characteristic of the source and at least one characteristic of the destination. The processor of the system determines a route for the transmission of the information based on the routing query signal and on the characteristics stored in the memory.  
           [0006]    In another aspect, the invention features a method for managing the routing of information to a destination through a plurality of networks, wherein at least one of the networks is a packet network and each network is linked to at least one other network by a communication medium. The method comprises the steps of:  
           [0007]    1) receiving a routing query signal specifying a destination to which the information will be routed;  
           [0008]    2) storing at least one characteristic of the destination; and  
           [0009]    3) determining a route for the transmission of the information based on the routing query and on the stored characteristics.  
           [0010]    In another aspect, the invention features a method for managing the routing information from a subscriber of a fixed wireless service network to a destination through a plurality of networks, wherein at least one of said networks is a packet network and wherein each network is linked to at least one other network by a communication medium. The method comprises the steps of:  
           [0011]    1) receiving a routing query signal from the subscriber of the fixed wireless service network;  
           [0012]    2) storing information concerning at least one characteristic of the destination at a routing processor;  
           [0013]    3) determining a transmission path for routing the information through the networks, the transmission path comprising elements of at least one of the networks in addition to elements of the packet network, wherein the step of determining the transmission path is based on the routing query signal and the stored characteristics;  
           [0014]    4) sending a routing response signal from the routing processor to the subscriber; and  
           [0015]    5) routing the information over the path.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    [0016]FIG. 1 is a block diagram illustrating a system for managing the routing of packets over a hybrid communication network in accordance with one embodiment of the present invention;  
         [0017]    [0017]FIG. 2 is a block diagram illustrating an embodiment of a base station of FIG. 1.  
         [0018]    [0018]FIG. 3 is a block diagram illustrating an embodiment of a remote unit of FIG. 1;  
         [0019]    [0019]FIG. 4 is a functional block diagram of a method for setting up a call using the system of FIG. 1;  
         [0020]    [0020]FIG. 5 is a functional subscriber block diagram of a method for determining a routing path to a PSTN subscriber destination and forwarding a call to said destination through such a path using the system of FIG. 1;  
         [0021]    [0021]FIG. 6 is a functional block diagram of a method for determining a routing path to a fixed wireless subscriber destination and forwarding a call to said destination through such a path using the system of FIG. 1; 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0022]    The present invention relates to routing packets of, for example, digitized voice, from a subscriber of fixed wireless services to a subscriber at a destination through a hybrid network. The subscriber at the destination being either a subscriber of fixed wireless services or POTS services.  
         [0023]    [0023]FIG. 1 shows a simplified hybrid communication network  10  suitable for use in accordance with an embodiment of the present invention. It will be recognized that the network of FIG. 1 includes other known elements, but those elements have been omitted for simplicity.  
         [0024]    Referring to FIG. 1, network  10  comprises at least one calling party location, such as location  30 , at least one information transfer network, such as fixed wireless network  10   a , Public Switched Telephone Network (PSTN)  10   b  or data network  10   c  (i.e. ATM based backbone) and at least one destination party location, such as locations  20  and  40 . Destination location  20 , subscribes to PSTN  10   b  and destination location  40  subscribes to network  10   a.    
         [0025]    A wired information transfer network, such as PSTN  10   b , generally comprises a plurality of conventional switches (not shown) that are interconnected to enable wired device  20  to communicate with other devices within or outside PSTN  10   b  via LEC  50 . The wired device may be a conventional telephone  20 , as illustrated in FIG. 1, or any other communication device (not shown) connected to PSTN  10   b  by various communications links  23   a  (e.g., analog, ISDN, etc). For example, wired device  20  could include facsimile devices, personal computers, modems, etc.  
         [0026]    Data network  10   c  includes a packet switched network, comprising, preferably, an Asynchronous Transfer Mode (ATM) subnetwork using protocols such as TCP/IP, X.25, ATM, etc. A data network such as network  10   c , generally comprises a plurality of packet routers for transmitting packets of data. The packets include address headers, error correction bits, synchronization bits and the like. It is understood that the present invention may be applied to any type of data packet subnetwork using the structures and methods described herein and is not limited to ATM subnetworks.  
         [0027]    Referring to FIG. 1, there is shown a simplified block diagram of a wireless communication network  10   a  forming part of a hybrid network  10 , its logical entities as well as its relative connection to PSTN  10   b  and data network  10   c . In the following description, the wireless communication network  10   a  is described in the context of a fixed wireless subscriber&#39;s telephone, such as device  30 . It will, however, be understood that the methods and systems of the present invention can be applied to other wired or wireless modem communication systems such as laptop computers and fax devices.  
         [0028]    Wireless communication network  10   a , as illustrated in FIG. 1, comprises a fixed wireless subscriber&#39;s telephone, such as devices  30  and  40 , remote units (RUs)  80  and  120 , and base stations (BSs)  70  and  110 . Typically, remote units  80  and  120  and base stations  70  and  110  each include a microprocessor (not shown) to control operations thereof.  
         [0029]    Base stations  70  and  110  and remote units  80  and  120  each have a transceiver. Such transceivers include any modulation/demodulation, filtering, and other signal processing circuitry required for communicating in accordance with protocol and modulation techniques supported by the wireless systems.  
         [0030]    Further, remote unit  80  is connected to device  30  by communication path  23   a  and base station  70  is connected to remote unit  80  by airlink channel  23   b . Similarly, remote unit  120  is connected to device  40  by a communication path  23   a  and base station  110  is connected to remote unit  120  by airlink channel  23   b . Communication path  23   a  may be any number of wire-line transport services such as analog, ISDN, Ti or El line, or any of a number of other wireless alternative links. Airlink channel  23   b  may be any wireless highway of fixed bandwidth that is used to transfer data between remote units  80  and  120  and base stations  70  and  110 , respectively, at fixed speeds. Devices  30  and  40 , remote units  80  and  120 , and base stations  70  and  110  use airlink channel  23   b  and communication path  23   a  to set up the call and to forward the voice or data to the destination device; the destination device being either a wireless device  40  or wired telephone  20 . Throughout the communication process, it is base station  70  that provides overall control and thereby ensures that the operation of the whole wireless system is supported and serviced.  
         [0031]    In operation, base stations  70  and  110  couple devices  30  and  40  to (PSTN)  10   b  or data network  10   c . As illustrated in FIG. 1, such coupling occurs through communication paths  23   a , access nodes  90  and  100 , Gateway  130  and switching units  60  and  140 . As indicated above, communication paths  23   a  may be any number of wire-line transport services such as analog, ISDN, T1 or E1 line, or any one of a number of other wireless alternative links. Access nodes  90  and  100  perform all the switching functions related to call delivery through data network  10   c . Nodes  90  and  100  are connected to data network  10   c , Gateway  130 , and base stations  70  and  110 . Switches  60  and  140  perform all the switching functions related to call delivery through PSTN  10   b . Switch  60  is connected between PSTN  10   b  and base station  70  and switch  140  is connected between PSTN  10   b  and base station  110 . Switch  140  is also connected between PSTN  10   b  and Gateway  130 . As is known in the art, switching units  60  and  140  typically consist of class ⅘ programmable digital switch with CCIS communications capabilities. Switching units  60  and  140 , can be for example, a 5ESS switch manufactured by AT&amp;T or any comparable digital switch made by other vendors, such as Northern TeleCom and Seimans.  
         [0032]    Gateway  130  includes a database and process unit (not shown). The database in Gateway  130  maintains an inventory profile of routings to fixed wireless network  10   a  and PSTN  10   b , all switching units (e.g., switching units  60  and  140 ) and all access nodes (e.g., access nodes  90  and  100 ). The database is used by Gateway  130  to determine a routing path to a fixed wireless subscriber, such as device  30 , when a call is originated from an analog telephone (POTS) user, such as telephone  20  to device  30 . Gateway  130  also uses the database to determine a routing path from an access node, such as node  90 , to a PSTN  10   b  subscriber, such as telephone  20 , when a call is originated from a fixed wireless subscriber telephone, such as device  30 , to an analog telephone (POTS) user telephone, such as telephone  20 .  
         [0033]    Database may include storage devices such as random access memory (RAM), read only memory (ROM) and/or programmable read only memory (PROM), an erasable programmable read-only memory (EPROM), an electronically erasable programmable read-only memory (EEPROM), a magnetic storage media (i.e., magnetic disks), or an optical storage media (i.e., CD-ROM), and such memory devices may also be incorporated into a processing unit. Processing unit (not shown) includes software and hardware used by Gateway  130  to perform internetworking functions, such as packetization and depacketization, between a fixed wireless subscriber, such as device  30 , and a POTS user, such as telephone  20 .  
         [0034]    Shown in FIG. 2 is a high-level block diagram of a base station FIG. 1 in accordance with the invention. Design and operation of such base stations are well known to ordinarily skilled artisans, and the ensuing description sets forth merely by way of example certain functional blocks and their interconnection as may be embodied in a base station which may be used in accordance with the present invention.  
         [0035]    The following discussion will focus on base station  70 , although base station  110  contains a similar database. Base station  70  includes a database  24  and processing unit  25 . The database  24  in base station  70  maintains an inventory profile record of all subscribers to the wireless service, identification numbers associated with other types of calls (e.g., calls to subscribers of PSTN  10   b ) and call routing information for all base stations in wireless service network  10   a . Database  24  may include storage devices such as random access memory (RAM), read only memory (ROM) and/or programmable read only memory (PROM), an erasable programmable read-only memory (EPROM), an electronically erasable programmable read-only memory (EEPROM), a magnetic storage media (i.e., magnetic disks), or an optical storage media (i.e., CD-ROM), and such memory devices may also be incorporated into processing unit  25 .  
         [0036]    Processing unit  25  in base station  70  includes software used by base station  70  to perform the communications processing and control functions between base station  70  and fixed wireless subscriber devices, such as device  30 , as well as all other control functions that are required for managing a call from such a device to a destination. For example, preferably, the software is used to determine a routing path based on the called party identification number (i.e. fixed wireless subscriber telephone or PSTN subscriber telephone).  
         [0037]    Shown in FIG. 3 is a high-level block diagram of remote units  80  and  120  in accordance with the invention. Design and operation of such remote units are well known to ordinarily skilled artisans, and the ensuing description sets forth merely by way of example certain functional blocks and their interconnection as may be embodied in a remote unit which may be used in accordance with the present invention.  
         [0038]    For simplicity, remote unit  80  will be described. It is understood, however, that remote unit  120  is similar to remote unit  80 . Although remote units  80  may communicate with base station  70  according to known analog communication techniques, preferably remote unit  80  employs digital communication techniques. Remote unit  80  comprises a network interface  26 , an adaptor  27  used for DTMF digit collection, DTMF decoder/generator  28  and a speech coding module  33 . Remote units  80  also includes a D/A converter  29  to perform conversion of digitally sampled speech signals to analog speech signals and an A/D converter  30  to perform conversion of analog speech signals to digitally sampled speech signals. Further, remote unit  80  contains a central processing unit  31  and memory unit  32 .  
         [0039]    The overall function of remote unit  80  is controlled by central processing unit  31 . Central processing unit  31  operates under control of executed computer program instructions which are stored in memory unit  32 . Memory unit  32  may be any type of machine readable storage device. For example, memory unit  32  may be a random access memory (RAM), a read-only memory (ROM) and/or a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electronically erasable programmable read-only memory (EEPROM), a magnetic storage media (i.e., magnetic disks), or an optical storage media (i.e., CD-ROM). Further, remote unit  80  may contain various combinations of machine readable storage devices which are accessible by central process unit  31  and which are capable of storing a combination of computer programs, instructions and data.  
         [0040]    The telephone network interface module  26  handles the interaction between remote unit  80  and fixed wireless subscriber&#39;s telephone, such as device  30 . Interface module  26  also handles the interaction between remote unit  80  and base stations, such as base station  70 .  
         [0041]    DTMF decoder/operator  28  converts DTMF tones into digital data. Speech coding module  33  performs compression and decompression of speech signals connecting at, for example, fixed wireless subscriber&#39;s telephone, such as device  30 , and received over communication path  23   a . Such speech signals are processed and converted into digital data by speech coding module  33 . Preferred low-rate digital voice coding (less than 16 Kbps) is used. The functionality of module  33  may be implemented in hardware, software or a combination of hardware and software, using well-known signal processing techniques.  
         [0042]    Remote unit  80  also perform functions such as switch-hook operations, hybrid, ring detect, line termination, on/off hook signal interface signals and the like.  
         [0043]    Referring to FIG. 4, there is illustrated an operational flow chart of how an embodiment of the present invention proceeds to set up a call in accordance with the system represented by FIG. 1. Referring now to FIG. 4, there is shown a flow diagram for a process executed by base station  70  in response to a call set up query placed by fixed wireless subscriber device  30  via remote unit  80 . Specifically, when a call is placed by device  30 , an off-hook signal is sent through communications path  23   a  to the transceiver of remote unit  80  (step  400 ). Remote unit  80  then sends a dial tone to device  30  indicating that it is ready to receive the called party&#39;s telephone number (step  401 ). Device  30  then sends DTMF signals to the transceiver of remote unit  80  via path  23   a  (step  402 ). The DTMF signals represent the call set up query and include the identification number corresponding to the destination. Remote unit  80  then sends a hold transmission message to device  30  (step  403 ) and remote unit  80  forwards the call set up query to the transceiver of base station  70  via airlink channel  23   b  (step  404 ).  
         [0044]    Base station  70  performs a database  24  look-up to identify the calling subscriber (step  405 ). Once the base station  70  processes the calling party features, it may perform any calling party based treatment (e.g., call blocking, reverse billing, etc.). Base station  70  then identifies the destination identification number, held in packet payload, and determines the subscriber service associated with the destination identification number (step  405 ).  
         [0045]    Specifically, base station  70  looks in database  24  to determine whether the destination identification number corresponds to a wireless subscriber, such as device  40 , or a PSTN subscriber, such as device  20  (step  406 ). Once base station  70  identifies the destination, base station  70  determines a routing path from device  30  to the destination based on base station&#39;s  70  knowledge of the network topology (step  407 ).  
         [0046]    Referring now to FIG. 5, an operational flow diagram is illustrated for the process executed by base station  70  in determining a routing path (step  407 ) based on a fixed wireless subscriber originated call (e.g., originating from device  30  of FIG. 1) placed to the destination number of a PSTN  10   b  subscriber (e.g. wired telephone  20  of FIG. 1).  
         [0047]    Base station  70  sends a routing query signal to Gateway  130  through access node  90 , data network  10   c  and access node  100 , respectively (step  408 ). Gateway  130  checks its database and determines a routing path from access node  100  to PSTN  10   b  subscriber device  20  through switching unit  140  and LEC  50 , respectively. Gateway  130  then sends the routing path information to base station  70  through access node  100 , data network  10   c  and access node  90 , respectively (step  409 ). Base station  70  then reserves the routing path by sending a reservation signal to Gateway  130  and Gateway  130  reserves the elements on the routing path (step  410 ). Once the network elements are reserved a reservation acknowledgement signal is sent from Gateway  130  to base station  70 , via access node  100 , data network  10   c  and access node  90 , respectively (step  411 ). Base station  70  then sends a routing path signal to device  30  via remote unit  80  (step  412 ).  
         [0048]    The routing path signal includes a signal informing remote unit  80  to turn transmission on and start transmitting the information. Device  30  sends voice information to remote unit  80 , via communication path  23   b  (step  413 ), and remote unit  80 , then digitizes and compresses such information (step  414 ). Remote unit  80  then forwards this digitized information to base station  70 , via airlink channel  23   b  (step  415 ) and base station  70  packetizes the information and forwards it to Gateway  130  through access node  90 , data network  10   c  and access node  100 , respectively (step  416 ). Gateway  130  depacketizes such voice information and forwards it to device  20 , through switching unit  140  and LEC  50 , respectively (step  417 ).  
         [0049]    An alternative method for routing a call to a PSTN  10   b  subscriber device  20  is through the standard circuit switched network without packetization. Specifically, a call is forwarded from base station  70  to device  20  through switching unit  60 , PSTN  10   b  and LEC  50 , respectively.  
         [0050]    Referring now to FIG. 6, an operational flow diagram is illustrated for the process executed by base station  70  in determining a routing path (step  407 ) based on a fixed wireless subscriber originated call (e.g., originating from device  30  of FIG. 1) placed to the destination number of another fixed wireless subscriber (e.g., device  40  of FIG. 1). Base station  70  performs database  24  look-up and determines a routing path to destination device  40  (step  418 ). Base station  70  then reserves the path by sending reservation signals to base station  110  through access node  90 , data network  10   c , and access node  100 , respectively (step  419 ). Base station  110  reserves the network elements on routing path (step  420 ). Once the network elements on the path are reserved, base station  110  sends acknowledgement signals to base station  70 , via access node  100 , data network  10   c , access node  90 , respectively (step  421 ). Base station  70  then sends a routing path signal to device  30  via remote unit  80 , respectively (step  422 ).  
         [0051]    The routing path signal includes a signal informing remote unit  80  to signal device  30  to turn transmission on and start transmitting the information. Device  30  then sends voice information to remote unit  80 , via communication path  23   b  (step  423 ), and remote unit  80 , then digitizes and compresses such information (step  424 ). Remote unit  80  then forwards this digitized information to base station  70 , via airlink channel  23   b  (step  425 ), and base station  70  packetizes the information and forwards it to wired device  40  through access node  90 , data network  10   c , access node  100  and base station  110 , respectively (step  426 ). Base station  110  depacketizes such voice information and forwards it to device  40  via remote unit  120  (step  430 ).  
         [0052]    Although the above description provides many specificities, these enabling details should not be construed as limiting the scope of the invention, and it will be readily understood by those persons skilled in the art that the present invention is susceptible to many modifications, adaptations, and equivalent implementations without departing from this scope and without diminishing its attendant advantages. It is therefore intended that the present invention is not limited to the disclosed embodiments but should be defined in accordance with the claims which follow.