KR100348599B1 - Gateway Apparatus for Voice Communication over Internet Protocol with Integrated Wireless Digital Network Facility - Google Patents

Abstract

The present invention relates to a gateway device for Voice over Internet Protocol (VoIP), and wirelessly interconnected with a mobile phone terminal equipped with a modem capable of supporting wireless communication such as a Bluetooth modem. Provided is a wireless internet gateway device supporting Internet voice communication through a network.

In order to achieve the above object, the gateway device of the present invention forms a digital network in an RF band through page scanning for at least one wireless voice terminal equipped with a wireless modem, and controls voice signals and calls with the wireless voice terminal. A wireless modem module for transmitting and receiving a signal including a signal; And an Internet telephone gateway which communicates with the wireless modem module and compresses voice signals from the signals received therefrom, converts them to RTP / UDP, and converts call control signals to TCP to transmit and receive them over the Internet. do.

Description

Gateway Apparatus for Voice Communication over Internet Protocol with Integrated Wireless Digital Network Facility

The present invention relates to a voice communication device on a digital network, and more particularly, to a gateway device for Voice over Internet Protocol (VoIP).

Conventional VoIP systems can be categorized into three methods: PC-to-PC, PC-to-phone, and phone-to-phone in terms of users. The PC-to-PC method is an initial method that does not require any hardware equipment other than the user interface, and call setup and voice communication are performed only through the Internet without passing through a PSTN or cellular network in the middle of a call path. However, practicality is greatly reduced such that only users who use the same VoIP system can make a call and have to make an appointment in advance. In the PC-to-phone method, the talker is a PC user who is directly connected to the Internet, and the talker is an existing network user. The voice is transmitted to the Internet near the receiver, and the signal is switched at the gateway located at the interface between the Internet and the existing communication network. Therefore, although the practicality and the scope of application are improved compared to the PC-to-PC method, the service provider must bear the charges accordingly because the final stage must pass through an existing communication network such as a public line switching network (PSTN) to which the receiver is connected. It is possible to make a phone call only through a PC, and there is a problem in that the method of use is more complicated than that of a conventional phone method. The most advanced form of VoIP technology, the phone-to-phone approach, allows a service provider to charge a user a fee, allowing the user to use an Internet phone much like a traditional phone call. In this case, because both the sender and the receiver are connected to the existing public network, a gateway is required at both interfaces between the Internet network and the existing communication network. However, in order to use this method, a separate Internet telephone must be purchased and the service identification number assigned to the Internet telephony service provider has not yet been transmitted from the exchange of the existing public line switching network to the service provider gateway. Since the user makes a call to the service provider and the call is established, the user has to press the user number and password to be authenticated and re-enter the recipient's phone number, which is still very inconvenient to use. In addition, even if the final call fails, there is a problem that someone has to pay the call charge to the service provider.

As such, the conventional VoIP system has not solved the problem of inconvenient user interface and additional communication cost in interface with the existing public network.

On the other hand, due to the proliferation of mobile phones and related additional services, personal mobile phones have been considered as a means of accessing various information services beyond the meaning of simple voice communication means to users. In addition, there is an attempt to provide a high-level service by establishing a network for organic internal communication between communication equipment including personal mobile phones and various multimedia products. Bluetooth, HomeRF, and IEEE802.11 are the ones involved in this attempt, and in particular the Bluetooth technology can be optimally employed in connection with the present invention. This technology is described in detail here on the Bluetooth homepage (www.bluetooth.net).

Bluetooth was established in February 1998 by Ericsson, Nokia, IBM, Toshiba, and Intel, five companies with technologies in mobile communications, computers, and core DSPs, with the formation of the Bluetooth Special Interest Group (SIG). Standard. One master, using frequency hopping (FH) CDMA techniques in the 2.4 GHz Industrial Scientific Medical (ISM) band, supporting point-to-point and point-to-multipoint connectivity between devices in close range (within 10 meters) Up to seven slaves can be connected. The transmission speed can be up to 1 Mbps, and data is transmitted through an asynchronous connectionless (ACL) link and a synchronous link oriented (SCO) link. In Bluetooth, first, use and authentication of FH CDMA, guarantee reliability through encryption, and second, provide low cost of a fairly small module, and third, ease of application service implementation through standardization of protocol on the physical layer. It has many advantages over other standards (eg IrDA, HomeRF, IEEE 802.11) and will be widely adopted in various multimedia devices in the future. Qualcomm, which produces chips for mobile handsets, announced that it will integrate Bluetooth modem functions into its own chipset for mobile handsets (ASICs). Each multimedia or communication device equipped with a Bluetooth modem establishes itself as a small local network (LAN) through a communication process similar to the communication between an existing mobile phone terminal and a base station and moves to a new network by paging processing when moving a region. do.

The present invention is to provide a gateway device capable of supporting a new type of Internet voice communication through communication with a mobile phone terminal employing such Bluetooth technology, the present invention has a simple structure of low cost, the use method is simple It is an object of the present invention to provide a gateway device capable of supporting Internet voice communication, which is convenient and convenient, and minimizes unnecessary billing at the interface with the public network.

It is another object of the present invention to provide a gateway device having a simple and economical structure including a general purpose processor through appropriate load balancing.

1 shows an overall Internet phone system using a gateway device according to a preferred embodiment of the present invention.

2 shows a schematic configuration of a wireless modem gateway 11 according to the present invention.

3 is a block diagram showing the overall configuration of the present invention.

Figure 4 shows an embodiment of a wireless modem gateway device according to a preferred embodiment of the present invention.

5 illustrates the structure of an H.323 protocol stack.

Explanation of symbols for main parts of the drawings

11: wireless modem gateway 12: mobile phone terminal

13: Internet Access Point 21: Internet Phone Gateway

22: wireless modem module 31: link manager

32: baseband processor 33: RF module

34: host protocol stack handler 35: media gateway

36: signaling gateway 37: network adapter

The gateway device of the present invention for achieving the above object provides an Internet gateway device that supports voice communication over the Internet protocol through a wireless network formed between a mobile phone terminal equipped with a modem capable of supporting wireless communication such as a Bluetooth modem. do.

The gateway device of the present invention for achieving the above object is a gateway device for voice communication on the Internet protocol, the device is:

A wireless network that forms a digital network in an RF band and transmits and receives a signal including a voice signal and a call control signal to the wireless voice terminal through at least one wireless voice terminal equipped with a wireless modem through a page scanning method. A modem module;

Among the signals communicating with the wireless modem module, the voice signal is compressed / restored and packetized / depacketized by the first protocol, and the call control signal is packetized / depacketized by the second protocol to be transmitted and received over the Internet. Telephone gateway; characterized in that it comprises a.

Here, the first protocol for carrying the voice signal is a protocol of a real-time oriented (CL) connection type, such as RTP / UDP, for example, and the second protocol for carrying a call control signal. The protocol focuses on the reliable transmission and reception of signals and is a protocol in the form of CO (connection-oriented), for example TCP. They are based on the same protocol layer, for example the same IP layer, as seen in the overall protocol hierarchy. A typical example of such an integrated protocol is the H.323 protocol stack. 5 shows the structure of an H.323 protocol stack. As such, the H.323 protocol stack defines upper layer communication protocols such as messages required for call setup and management based on the transport layer protocol (UDP / TCP) and the network layer protocol (IP: Internet Protocol). have. Recently, standard standards for compatibility between voice communication devices on Internet protocols such as SIP / MGCP (Session Initiation Protocol / Media Gateway Control Protocol) as well as the H.323 protocol have been proposed. There may be a plurality of wireless telephone terminals communicating with the gateway device of the present invention. For example, according to the Bluetooth standard, up to seven slaves can be connected to one master, and the SCO link, a channel for dual voice signal transmission, can be connected to three at the same time from one master. If adopted, up to three wireless telephone terminals can simultaneously use the Internet phone by using the gateway device of the present invention.

Furthermore, the gateway device of the present invention

A gateway device for voice communication on an internet protocol, the device comprising:

An RF module for performing wireless communication in at least one wireless voice terminal equipped with a wireless modem in an RF band, and performing a frequency shift between the RF band and the base band with respect to the wireless communication signal;

A baseband processor for modulating and demodulating the baseband signal to or from the RF module and converting it into a binary signal; and

A link manager configured to perform page scanning on the at least one wireless voice terminal through a binary signal transmitted and received with the baseband processor to establish and manage a wireless digital network with the baseband processor; and

A wireless modem protocol stack processor which extracts a call control signal through a communication protocol corresponding to each network layer through a binary signal transmitted and received with the baseband processor;

A wireless modem module comprising a;

A media gateway for compressing and restoring a voice signal communicating with the baseband processor; and

Packetized / depacketizes a compressed voice signal of a signal communicating with the media gateway using a first protocol, and transmits a signal for call setup / control / release to communicate with the wireless modem protocol stack processor. A signaling gateway that converts to fit the protocol and performs packetization / depacketization processing using the second protocol; and

A network adapter for transmitting and receiving a packetized first or second protocol signal received from the signaling gateway to the Internet;

Characterized in that it comprises a.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily understand and reproduce.

The present invention provides a mobile phone terminal equipped with a modem capable of supporting wireless communication, and an Internet gateway device supporting voice communication over an Internet protocol through a wireless network. Such a wireless network may be any device that can establish a new gateway as a master by scanning a page when providing a wireless network between devices and deviating from an appropriate range, but one preferred embodiment of the present invention is to adopt a Bluetooth modem. do. A preferred embodiment of the present invention is also described using a cordless telephony (CT) profile of the operation profile of a Bluetooth modem. However, the present invention is not limited to this profile and may use, for example, a Bluetooth headset profile.

The basic Bluetooth CT profile works as follows.

o A wireless terminal that is out of range of its gateway periodically searches for a new gateway through paging.

o The gateway scans pages using the maximum free capacity available so that wireless terminals entering the gateway range can find the gateway as soon as possible.

o When the wireless terminal pages the gateway, the gateway always acts as a master, so a master-slave switch occurs.

o Wireless terminals that are not used for a call but are within gateway range are in power saving mode (park) mode to prevent time delays during call setup.

o It provides security of call contents through authentication and encryption between gateway and wireless terminal.

Since the operation of the Bluetooth CT profile is a fairly common technique in the art, various methods may appear before or after the filing date of the present invention, but the present invention may be applied in any manner as long as such operations are supported.

1 shows an entire Internet phone system using a gateway device according to a preferred embodiment of the present invention. This system is largely summarized into three aspects: mobile phone terminal 12 equipped with a Bluetooth modem, wireless modem gateway 11, and Internet access point 13. The mobile phone terminal 12 equipped with Bluetooth is composed of a Bluetooth modem and a profile for controlling it internally, and converts a user's voice into a PCM signal and a call signal generated from a number inputted by the user to set up a call. It performs wireless transmission to the wireless modem gateway, and processes the call control signal transmitted by the wireless modem gateway 11 and outputs voice. Such a function can be universally supported in a Bluetooth modem or a mobile telephone terminal equipped with a modem of the same type or a cordless telephone terminal equipped with the same modem. The wireless modem gateway 11 makes a wireless connection with the mobile telephone terminal 12, converts the digital voice signal and the call control signals, and transmits and receives with the other party through the Internet access point 13. The Internet access point 13 is a point for actually transmitting a communication packet generated by the wireless modem telephone gateway 11 to the Internet, and serves as one end point that constitutes a LAN.

2 shows a schematic configuration of a wireless modem gateway 11 according to the present invention. As shown, the wireless modem gateway 11 is composed of a wireless modem module 21 and an internet telephony gateway 22. The wireless modem module 21 supports the same communication protocol according to a communication protocol such as a CT-profile or a modified headset profile for transmitting and receiving voice PCM signals and call signals, for example, by incorporating a Bluetooth modem, The mobile telephone terminal 12 is connected wirelessly. The wireless modem module 21 transmits and receives a call control signal and a voice PCM signal to and from the Internet telephone gateway 22 through the paths of (divalent) and (2b), respectively. The Internet telephony gateway 22 performs call setup and release according to the international standard protocol for setting up and releasing multimedia communication through the Internet, for example, H.323 protocol, and compresses the voice PCM signal by a voice compression algorithm. Packets are transmitted to the Internet access point 13 or the compressed voice signal transmitted from the Internet access point 13 is transmitted to the wireless modem module 21.

3 is a block diagram showing the overall configuration of the present invention. Referring now to Figure 3, the wireless modem gateway 11 of the present invention will now be described in detail. Here, the "modem reception operation" refers to a process in which the wireless modem gateway 11 receives a signal from the mobile telephone terminal 12, and the "modem transmission operation" refers to a wireless modem gateway 11 in the mobile telephone terminal. Refers to the process of transmitting a signal to (12).

The wireless modem module 21 constituting the wireless modem gateway 11 includes a link manager 31, a baseband processor 32, an RF module 33, and a host protocol stack processor 34 as shown in FIG. do. In the case of the modem reception operation, the RF module 33 receives the radio signal transmitted from the mobile telephone terminal 12 using the 2.4 GHz frequency band, and properly amplifies / filters / dehoppings / basebands the radio signals. To the baseband processor 32. In the case of a modem transmission operation, the RF module 33 performs a radio transmission by shifting the signal modulated by the baseband modem 32 to a frequency hopping frequency band of 2.4 GHz. In the case of the reception operation, the baseband processor 32 demodulates the baseband signal transmitted by the RF module 33 into a binary signal. In the case of the modem transmission operation, the baseband processor 32 modulates the binary signal of the packet generated by the link manager 31 and the host protocol stack processor 34 and transmits it to the RF module. The link manager 31 performs link establishment and management between Bluetooth terminals. The host protocol stack handler 34 performs a service defined by each layer of the Bluetooth host protocol stack, and extracts a message for a final application such as a call establishment / control / release message from a packet received from the baseband processor. . The Bluetooth protocol stack includes baseband protocols, link manager protocol (LMP), logical link control adaptation protocol (L2CAP), service discovery protocol (SDP), RFCOMM, telephony control specification-binary (TCS-bin), and host control interface (HCI). Etc., such as Lungworm, HCI, L2CAP, SDP, RFCOMM, TCS-bin, etc. are the Bluetooth host protocol stack. The host protocol stack processor 34 communicates with the baseband processor (trivalent), which is implemented using a host controller interface (HCI). For modem receive operation, the voice PCM signal is sent from the baseband processor directly (2) to the Internet telephony gateway 21, which is a synchronous connection oriented (SCO) link defined in the baseband protocol of the Bluetooth protocol stack. Is implemented. Even in the modem transmission operation, the voice PCM signal transmitted from the Internet telephone gateway 21 is directly transmitted to the baseband processor 32 via (2b).

The Internet telephony gateway 21 is composed of a media gateway 35, a signaling gateway 36, and a network adapter 37 as shown. The media gateway 35 compresses the voice signal received from the baseband processor 32 of the wireless modem module 22 and transmits the compressed voice signal to the signaling gateway 36, while receiving the compressed voice signal received from the signaling gateway 36. It decompresses and transmits the signal to the baseband processor 32 of the wireless modem module, and performs an echo cancellation function on the voice signal if necessary. The signaling gateway 36 implements a multimedia communication standard protocol stack through the Internet, such as H.323 or SIP / MGCP. The signaling gateway 36 is connected to the host protocol stack processor 34 of the wireless modem module 22 to provide signals for call setup. (2) send and receive in the form of a message, call establishment / control / release message according to the multimedia communication standard protocol over the Internet and the corresponding protocol (eg TCS-bin) of the host protocol stack of the wireless modem module 22 Performs mutual conversion and connection between call establishment / control / release messages.

In the preferred embodiment of the present invention, in the case of the reception operation, the media gateway 35 transmits the PCM signal of the voice transmitted by the wireless modem module 22 through (2b) to G.711, G.723.1, and G.729. It compresses by a standard voice compression algorithm such as and delivers it to the signaling gateway 36. At this time, the media gateway 35 and the signaling gateway 36 perform packet communication according to an arbitrarily defined protocol. In the case of the transmission operation, the media gateway 35 analyzes the packet delivered by the signaling gateway 36 to extract the compressed voice signal and restores it by the restoration process of the voice compression algorithm. Transfer to 22. The media gateway 35 is preferably implemented using a digital signal processor (DSP) suitable for complex voice signal processing.

The signaling gateway 36 includes a system implementing TCP / IP and a multimedia communication protocol (H.323, SIP, etc.) operating thereon, and serves as the overall management of the Internet telephony gateway 21. In the case of the reception operation, the signaling gateway 36 converts the compressed voice signal generated by the media gateway 35 into a packet defined by the RTP / UDP / IP and delivers it to the network adapter 37.

When a signal for setting / controlling / releasing a call is transmitted from the wireless modem module 21 through (2), TCP / IP is converted into a message defined by the multimedia communication protocol over the Internet. The packet is defined and delivered to the network adapter 37. In the case of the transmission operation, the packet received from the network adapter 37 is interpreted, and in the case of a signal for setting / controlling / releasing a call, the packet is converted into a message format conforming to the wireless modem protocol protocol, and the wireless modem module ( 21), and in the case of a compressed voice signal, a packet is generated according to a protocol defined between the media gateways 35 and transmitted to the media gateway 35. The signaling gateway 36 is preferably implemented using a RISC type microcontroller suitable for protocol implementation and control of the entire system. In addition, since the host protocol stack processor 34 of the wireless modem module 21 is also generally implemented as a microcontroller separate from the baseband processor, the host protocol stack processor 34 and the signaling gateway in the preferred embodiment of the present invention. Implementing 36 in one microcontroller can reduce the overall system cost. In this case, the host protocol stack processor 34 and the signaling gateway 36 are each implemented as independent tasks on one processor, and the (bivalent) path between the two is interpreted as a logical path that does not exist physically. In this case, the (trivalent) path between the host protocol stack processor 34 and the baseband processor 32 is preferably implemented as an HCI UART transport layer among the HCI protocols defined by the Bluetooth protocol. When the signaling gateway 36 and the media gateway 35 are each implemented as separate processors using a microcontroller and a DSP, the signaling gateway 36 directly accesses a memory area of the media gateway 35 to perform communication with each other. It is preferable to do this, and this can be mainly implemented by standard methods such as HPI (Host Port Interface).

The network adapter 37 serves to connect the wireless modem gateway 11 with the Internet access point 13. The network adapter 37 is composed of a network controller for generating or interpreting signals defined at the data link layer and a network transceiver for generating actual physical signals.

A concrete implementation of the present invention is made possible by efficiently distributing the massive voice compression portion and other signaling processing to the appropriate processors and ensuring proper communication between these processors. The wireless modem gateway device according to the present invention for voice communication on such an Internet protocol is:

A wireless modem module excluding a host protocol stack processor that supports the Bluetooth standard;

A digital signal processor (DSP) for compressing and restoring a voice signal communicating with the modem module according to a standard voice compression algorithm;

The compressed voice signal, which is communicated and communicated through the digital signal processor and the host port interface (HPI), is packetized / depacketed using a first protocol and a signal for call setup / control / release is second. A microprocessor configured to perform packetization / depacketization processing using a protocol, and to process a Bluetooth host protocol stack;

Memory accessed by the microprocessor and digital signal processor;

And a network interface for transmitting and receiving the packet generated by the microprocessor to the Internet.

Figure 4 shows an embodiment of a wireless modem gateway device according to a preferred embodiment of the present invention. Bluetooth modems, except for host protocol stack handlers, are modular, and Internet telephony gateways are digital signal processors (DSPs) for processing high-volume parts such as media gateway's voice compression algorithms, signaling gateway functions, and Bluetooth host protocol stack processing. It is divided into MCUs to handle functions, connection and conversion functions between the two functions, and connection functions with a network interface. The two processors communicate with each other using a host port interface (HPI). For example, a Texas Instruments TMS320C54x, which can handle four to five channels simultaneously, can be used as a DSP, and a microprocessor such as ARM7 can be used as a RISC CPU. The MCU's output is sent to the Internet via a network interface. The network interface sends a packet generated by a signaling gateway (MCU) to an ADSL, a cable, or an Ethernet line. Usually, the network interface card has its own serial ROM or boot ROM, but in this embodiment, since the flash memory managed by the MCU can be used, a separate ROM is not required. The two processors may use the same memory physically, and these memory structures may be appropriately modified in consideration of economics and the like. The physical layer and the MAC protocol are implemented as Ethernet controllers and Ethernet transceivers, and the IP / TCP / UDP protocol is implemented in software. The hardware includes MAC control to detect and prioritize collisions on multiple channels and includes interfaces between the receiving FIFO, the sending FIFO, buffer management, the DMA channel engine, and the signaling gateway. In software, TCP is used for reliable packet transmission, including flow control, UDP is used for real-time transmission of voice packets, and IP is the source and destination at the lower network layer. Implemented for data encapsulation, including the address of. The Ethernet driver controls the operation of the DMA and the operation of the Ethernet controller by appropriately setting the registers in the Ethernet controller.

As described in detail above, the wireless modem Internet gateway device according to the present invention uses an existing general mobile phone equipped with a wireless modem without going through an existing public network in a home or office (discussed at the receiver stage separately). Internet phone service can be supported to minimize additional charges, and by appropriate user interface settings within the mobile phone (for example, all calls within the Bluetooth communication area are automatically connected to the Internet phone, By manually entering one additionally selected key and initiating a call, such as a manual connection to an Internet phone, mobile phone users have a new effect of making Internet phone calls extremely easy with a nearby wireless modem Internet gateway. In addition, the gateway device of the present invention ensures proper functional load distribution and communication between processors and is excellent in terms of economy and efficiency through a simple structure.

Although the present invention has been described with reference to specific embodiments, it is not limited thereto, and various changes may be made by those skilled in the art without departing from the scope of the present invention in each component. Thus, including such described or obviously foreseeable variations, the scope of the present invention will be limited only by the matters set forth in the claims.

Claims (3)

A gateway device for voice communication on an internet protocol, the device comprising: A wireless modem module for forming at least one wireless voice terminal equipped with a wireless modem through paging scanning to form a digital network in an RF band and transmitting and receiving a signal including a voice signal and a call control signal with the wireless voice terminal; ; Among the signals communicating with the wireless modem module, the voice signal is compressed / restored and packetized / depacketized by the first protocol, and the call control signal is packetized / depacketized by the second protocol to be transmitted and received over the Internet. And a telephone gateway. A gateway device for voice communication on an internet protocol, the device comprising: An RF module for performing wireless communication in at least one wireless voice terminal equipped with a wireless modem in an RF band, and performing a frequency shift between the RF band and the base band with respect to the wireless communication signal; A baseband processor for modulating and demodulating the baseband signal to or from the RF module and converting it into a binary signal; and A link manager configured to perform paging scanning on the at least one wireless voice terminal through a binary signal transmitted and received with the baseband processor to establish and manage a wireless digital network with the baseband processor; A wireless modem protocol stack processor which extracts a call control signal through a communication protocol corresponding to each network layer through a binary signal transmitted and received with the baseband processor; A wireless modem module comprising a; A media gateway for compressing and restoring a voice signal communicating with the baseband processor; and Packetized / depacketizes a compressed voice signal of a signal communicating with the media gateway using a first protocol, and transmits a signal for call setup / control / release to communicate with the wireless modem protocol stack processor. A signaling gateway that converts to fit the protocol and performs packetization / depacketization processing using the second protocol; and A network adapter for transmitting and receiving a packetized first or second protocol signal received from the signaling gateway to the Internet; An internet telephony gateway comprising a; Wireless Internet telephony gateway device comprising a. A gateway device for voice communication on an internet protocol, the device comprising: A wireless modem module excluding a host protocol stack processor that supports the Bluetooth standard; A digital signal processor (DSP) for compressing and restoring a voice signal communicating with the modem module according to a standard voice compression algorithm; The compressed voice signal, which is communicated and communicated through the digital signal processor and the host port interface (HPI), is packetized / depacketed using a first protocol and a signal for call setup / control / release is second. A microprocessor configured to perform packetization / depacketization processing using a protocol, and to process a Bluetooth host protocol stack; Memory accessed by the microprocessor and digital signal processor; And a network interface configured to transmit and receive the packet generated by the microprocessor to the Internet.