Abstract:
Minimizing the effects of the requisite AGWN packets on transmission channel utilization without diminishing any of the aesthetic quality of the AGWN white noise on the voice or audio communication. A system for minimizing the effect of required generated background noise on said transmission channel utilization comprising the combination of an implementation for forming a transmission stream of sequential digital audio data packets, associating with each audio packet a data code representation of the payload data packet enabling the generation of said background noise and an implementation at a receiving station, responsive to each of said data representations for forming the represented payload data packet enabling said generation of background noise together with means at said receiving station for interspersing said formed payload packets enabling background noise generation between said associated audio data packets and background noise generating means, at said receiving station, responsive to said enabling payload packets for generating the background noise between the audio data packets.

Description:
TECHNICAL FIELD 
   The present invention relates to telecommunications systems and particularly to systems for generating white noise required for audio or voice telecommunications. 
   BACKGROUND OF RELATED ART 
   With the globalization of business, industry and trade wherein transactions and activities within these fields have been changing from localized organizations to diverse transactions over the face of the world, the telecommunications industries have, accordingly, been expanding rapidly. While telecommunications technology development has been advancing to keep pace with expanded demands, communication channel bandwidth remains a relatively costly commodity. Bandwidth is the amount of data that can be transmitted via a given communications channel in a given unit of time (generally one second). Channel and bandwidth shortages still remain the factors that limit the full effectiveness of long distance telecommunications; particularly the cost of long range mobile telecommunications. Because of the rapid expansion of industry and commerce telecommunication bandwidth needs over the past decade, the telecommunications industry has been rapidly expanding the worldwide infrastructure needed to satisfy these needs. 
   One area has been that of Internet Protocol (IP) Telecommunications wherein voice and other audio telecommunications are transmitted over the Internet. In such IP telephonic communications, as well as in most of the conventional wired and wireless Public Service Telephone Network (PSTN) communications, voice communication is broken down into voice packets that are digitized and transmitted over either the traditional PSTN or over the Internet using IP telecommunication Protocols. The text,  IP Telephony Demystified , Ken Camp, published 2003, McGraw-Hill, New York, N.Y., describes such transmission of voice packets, particularly in Chapter three, pp. 54-69. These voice packets are generally transmitted by forward packet switching wherein the voice packets are switched at nodes where such packets are stored in queues until spaces in transmission streams arrive at the node to accept the voice packet. Such packet switched telecommunications are quite concerned with the quality of the telephone call. One conventional way to maintain quality of the voice transmission, even during silent periods, is to maintain a level background noise known as white noise. In order to maintain such background white noise, the technology has been interspersing white noise generating packets between transmitted voice packets. These white noise packets contain data for driving white noise generators maintained at receiving telephone stations for converting the data in the white noise packets into generated noise that is interleaved into the audible telephone signal at times of voice silence between voice packages. The most effective white noise generation is currently being done by the Additive Gaussian White Noise (AGWN) generator described in  Newton&#39;s Telecom Dictionary,  2003, CMP Books, San Francisco, Calif., on page 885; and in more detail in the published article,  Generating Noise in VoIP Designs , by F Bourget, Octasic System Design, Mar. 3, 2003, http://www.eedesign.com/story/OEG20030303S0036. While the white noise generated has maintained telephone audible quality, the packets needed for white noise generation, AGWN packets, have become so prevalent in telecommunication channels that channel utilization, i.e. that portion of the transmission channel used for the transmission of data content, has been significantly diminished. 
   SUMMARY OF THE PRESENT INVENTION 
   The present invention provides for minimizing the effects of the requisite AGWN packets on transmission channel utilization without any diminishing of the aesthetic quality of the AGWN white noise on the voice or audio communication. To this end, the present invention provides a system for minimizing the effect of required generated background noise on said transmission channel utilization comprising the combination of an implementation for forming a transmission stream of sequential digital audio data packets, means for associating with each audio packet, a data code representation of the payload data packet enabling the generation of said background noise, and an implementation at a receiving station, responsive to each of said data representations for forming the represented payload data packet enabling said generation of background noise together with means at said receiving station for interspersing said formed payload packets enabling background noise generation between said associated audio data packets, and background noise generating means, at said receiving station, responsive to said enabling payload packets for generating the background noise between the audio data packets. In an embodiment, the data code may be as simple as code defining the desired amplitude and duration of each white noise AGWN packet definition. According to one aspect of the invention, the associated data code representations of the payload data packet enabling the generation of said background noise are included in each voice data packet. 
   In accordance with a significant aspect of this invention, the telecommunications system of claim  4  is an IP telecommunications system; and there are further means for interposing Internet page packets into said transmitted stream whereby said Internet page packets are sequenced in spaces between voice packets conventionally occupied by the AGWN packets. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be better understood and its numerous objects and advantages will become more apparent to those skilled in the art by reference to the following drawings, in conjunction with the accompanying specification, in which: 
       FIG. 1  is a generalized diagrammatic view of a portion of a PSTN gatewayed to an IP Telecommunications network portion on which the present invention may be implemented; 
       FIG. 2  is a block diagram of a generalized display computer system including a processor unit that may perform the functions of the display computers through which the IP telecommunications may be transmitted (TX) and received (RX); 
       FIG. 3  is an illustration of a transmission channel having a voice packet transmission according to the prior art: 
       FIG. 4  is an illustration of a transmission channel having a voice packet transmission according to the present invention; 
       FIG. 5  is an illustration of a voice packet transmission processed at a telecommunication receiving station according to the present invention; and 
       FIG. 6  is a flowchart describing how the telecommunications system of the present invention is set up to minimize the effect of AGWN packets on transmission channel utilization. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring to  FIG. 1 , there is shown a generalized diagrammatic view of a portion of a PSTN Environment showing channel paths to and from both conventional wired and mobile wireless channels and devices. There is also an interconnected portion of an IP Telephony Environment involving transmissions over the Internet or Web. In the following discussion, it should be understood that the concepts described relate to packet transmission channels respectively within the PSTN Environment, the IP Environment or across both environments connected through an appropriate gateway to be hereinafter described in greater detail. The PSTN network includes channel paths to and from both conventional wired and mobile wireless channels and cellular devices according to the present invention. Let us assume that representative cellular telephone  38  of the many mobile cell phones that are in regions within the range of the cellular area set up as represented by cell tower  33  connected to a cell base station  36  that in turn is connected to switching center  35  that then routes the telecommunications into PSTN  30  to which conventional hardwired telephone stations as represented by telephone  37 . While, for convenience in illustration, both wireless mobile telephone  38  and wired telephone  37  are shown as ordinary telephones, it should be understood that these telephone stations are very likely to be computers, connected to the Web  50  through the PSTN connected via  72  to Web Server  53 , in turn connected to the Web  50  and thus into the IP environment via connection  71 . 
   Because wireless mobile communications, particularly from handheld or laptop computers is becoming very prevalent in PSTN systems, some background on wireless telecommunication is appropriate at this point. In the widely used cellular system for mobile wireless telecommunications, an area, such as a city, is broken up into small area cells. Each cell is about 10 square miles in area. Each has its base station that has a tower for receiving/transmitting and a base connected into PSTN. Even though a typical carrier is allotted about 800 frequency channels, the creation of the cells permit extensive frequency reuse so that tens of thousands of people in the city can be using their cell phones simultaneously. Cell phone systems are now preferably digital with each cell having over 160 available channels for assignment to users. In a large city there may be hundreds of cells, each with its tower and base station. Because of the number of towers and users per carrier, each carrier has a Mobile Telephone Switching Office (MTSO) that controls all of the base stations in the city or region and controls all of the connections to the land based PSTN. When a client cell phone gets an incoming call, MTSO tries to locate in what cell the client mobile phone is located. The MTSO then assigns a frequency pair for the call to the cell phone. The MTSO then communicates with the client over a control channel to tell the client or user what frequency channels to use. Once the user phone and its respective cell tower are connected, the call is on between the cell phone and tower via two-way long range RF communication. In the United States, cell phones are assigned frequencies in the 824-894 MHz ranges. Since transmissions between the cell telephone and cell tower are digital, but the speaker and microphone in the telephone are analog, the cell telephone has to have a D to A converter from the input to the phone speaker and an A to D converter from the microphone to the output to the cell tower. 
   Now, with respect to the Web IP Telephony of  FIG. 1 , environment protocols are described in detail in the above-mentioned text,  IP Telephony Demystified , particularly in Chapter 4, pp. 97-117. The IP network is customarily connected into the PSTN via a gateway, not specifically shown, but which may be part of the Web Access Server system  53 . The  IP Telephony Demystified  text describes several conventional gateways between PSTN and IP telecommunications networks at Chapter 7, pp. 145-156. 
   Before going further into the details of specific embodiments using the IP network in  FIG. 1 , it may be helpful to consider the Internet or Web from a more general perspective. For details on Internet nodes, objects and links, reference is made to the text,  Mastering the Internet , G. H. Cady et al., published by Sybex Inc., Alameda, Calif., 1996. The Internet or Web is a global network of a heterogeneous mix of computer technologies and operating systems. Higher level objects are linked to lower level objects in the hierarchy through a variety of network server computers. 
   With respect to the IP network of  FIG. 1 , the representative telephone stations  27  and  28  may be conventionally wired into the Web  50  as shown. Each telephone station  27 - 28  has an associated Web network terminal  15  and  17  with displays  57  upon which the screen panels  56  may be displayed. Terminals  15  and  17  may be implemented by the computer system set up to be subsequently described in  FIG. 2 , and the Network connection in  FIG. 2  is the Web connection  51  shown in  FIG. 1 . For purposes of the present embodiment, terminals  15  and  17  are representative of the Web display stations for respectively supporting and monitoring telephone stations  27 - 28 . Reference may be made to the above-mentioned  Mastering the Internet , pp. 136-147, for typical connections between local display stations to the Web via network servers; any of which may be used to implement the system on which this invention is used. In addition to the above-described standard dial-in or dial-out, the Web or like browser program associated with computer terminals  15 ,  17  (to be described in  FIG. 2 ) may be modified with application programs that will dial telephone stations  27  and  28  directly into a PSTN as indicated in  FIG. 1 . 
   Referring to  FIG. 2 , a typical data processing system is shown that may function as the computer controlled network terminals or Web stations  15  and  17 ,  FIG. 1 , the telecommunications or for data processing in any Web access server. 
   A central processing unit (CPU)  10 , may be one of the commercial microprocessors in personal computers available from International Business Machines Corporation (IBM) or Dell Corporation; when the system shown is used as a server computer at the Web distribution site to be subsequently described, then a workstation is preferably used, e.g. RISC System/6000™ (RS/6000) series available from IBM. The CPU is interconnected to various other components by system bus  12 . An operating system  41  runs on CPU  10 , provides control and is used to coordinate the function of the various components of  FIG. 1 . Operating system  41  may be one of the commercially available operating systems such as the AIX 6000™ operating system available from IBM; Microsoft&#39;s Windows XPT™ or Windows2000™, as well as UNIX and other IBM AIX operating systems. Application programs  40 , controlled by the system, are moved into and out of the main memory Random Access Memory (RAM)  14 . These programs include the programs of the present invention for implementing the modified telecommunication white noise packet and voice packet transmission in accordance with this invention. Any conventional Web browser application program, such as Microsoft&#39;s Internet Explorer™, or Lotus Notes™ Personal Web Navigator or Server Web Navigator will be available on terminals  15  and  17  for the voice and white sound packet receiving and sending. A Read Only Memory (ROM)  16  is connected to CPU  10  via bus  12  and includes the Basic Input/Output System (BIOS) that controls the basic computer functions. RAM  14 , I/O adapter  18  and communications adapter  34  are also interconnected to system bus  12 . I/O adapter  18  communicates with the disk storage device  20 . Communications adapter  34  interconnects bus  12  with the outside network enabling the computer system to communicate with other such computers over the Web or Internet. I/O devices are also connected to system bus  12  via user interface adapter  22  and display adapter  36 . Keyboard  24  and mouse  26  are all interconnected to bus  12  through user interface adapter  22 . It is through such input devices that the user at a receiving station may interactively relate to the Web in order to access Web documents and telecommunication packets. Display adapter  36  includes a frame buffer  39  that is a storage device that holds a representation of each pixel on the display screen  38 . Images may be stored in frame buffer  39  for display on monitor  38  through various components, such as a digital to analog converter (not shown) and the like. By using the aforementioned I/O devices, a user is capable of inputting information to the system through the keyboard  24  or mouse  26  and receiving output information from the system via display  38 . 
     FIG. 3  shows a conventional transmission channel for a packet switched telecommunication in a PSTN environment. TX  61  is the illustrative source of the transmission that includes voice packets  63  and  65 , and for each voice packet, a corresponding white noise (AGWN) packet  64 ,  66  that are referred to as a payload packet because each includes all of the data necessary to drive the AGWN generator apparatus at the receiving RX station of the transmission. It should be noted that for convenience in illustration, the voice packets and their associated AGWN packets are shown in the transmission channel in the sequence in which they would be converted into sound by the telephone receiving system associated with RX  62 . 
   Actually, in packet switching transmission, the packets are not likely to be positioned in sequence in transmission channels. The packets need not even move in the same channel as long as when they reach RX  62  the packets are in the sequence shown so that the appropriate AGWN white noise sequence may be generated between the associated voice generation. This should be understood when the present invention is described with respect to  FIGS. 4 and 5 . Accordingly, as will be described, the advantage of the present invention is not that the particular AGWN payload packet is directly eliminated from the transmission channel to leave a space into which another packet may be directly inserted. Rather, the advantage is that by eliminating the AGWN packets from the transmission channel, traffic in the channel is substantially reduced to thereby leave space into which a variety of transmitted packets may be inserted. 
   In the present invention, as shown in  FIG. 4 , instead of the discrete AGWN packets, a small amount of noise code  67  is transmitted, usually in association with the related voice packet  63 ,  65 . This associated code may actually be directly attached to the voice packet, e.g. a header. The code may merely be sufficient to define the amplitude and duration of the AGWN white noise from which the AGWN packet may be subsequently created at the receiving end RX  62  of the telecommunication, as will be described with respect to  FIG. 5 . Thus, there is room in the transmission channel for additional packets to be transmitted. In an IP environment, as shown, page payload packets  68  and  69  that are inserted, may be Web document packets being transmitted for any Web distribution function. Now, as illustrated in  FIG. 5 , at the RX end, where the voice telecommunication voice stream is reassembled by programming that may be implemented in the Web browser at the receiving station. Page payload packets  68  and  69  are removed if they have not previously been removed. Then the full AGWN data (payload) packets  74  and  76  are formed based upon the data defined by the respective codes  67 . Now, the voice data stream at the receiver end in  FIG. 5  has the same final structure as the conventional voice stream of  FIG. 3 , and thus, white noise (AGWN) packets  74 ,  76  are full payload packets including all of the data necessary to drive the AGWN generator apparatus at the receiving RX station of the transmission to insert the white noise of appropriate amplitude and duration between the speech generated from the respective voice packages  63  and  65 . 
     FIG. 6  is a flowchart showing the development of a system according to the present invention for maximizing transmission channel utilization in packet telecommunications. In IP telecommunications, provision is made for the transmission from TX to RX of a data stream of sequential packets, step  81 . In this sequential data stream, a protocol is established wherein there is transmitted, in association with each voice packet, data code representative of the content (payload) of an AGWN white noise packet, step  82 . Provision is made for the insertion, between voice packets in the data stream in the transmission channel, of packets of Internet pages or documents, step  83 . At a receiving point in the network, provision is made for the timely removal of any packets of Internet page packets and for the further distribution of such page packets to further points on the Internet, step  84 . At the receiving point of the transmission, provision is made for the conversion of the data code of step  82  to form each AGWN packet between the respective voice packets, step  85 . Provision is made for the conventional generation of telephonic sound from the conversion of each sequential voice packet, step  86 . Provision is made for a white noise generator for converting each sequential AGWN packet into white noise respectively interspersed with the units of sound of step  86  to provide a complete telephonic audio sound, step  87 . 
   Although certain preferred embodiments have been shown and described, it will be understood that many changes and modifications may be made therein without departing from the scope and intent of the appended claims.