MXPA01000422A - Method and apparatus for establishing tdd/tty service over vocoded channels - Google Patents

Abstract

A method and apparatus for establishing low activity communication service over vocoded channels in a digital telecommunications system, which may include wireless links. In one embodiment, once the telecommunication system receives a low activity communication signal (402), all vocoders automatically lock into a full rate (404) in preparation for transmission. Where applicable, the transmission power of the low activity communication signal is adjusted to reduce frame error rate (408). Dynamic adjustments are made continually during transmission (412). The telecommunications system includes apparatus to notice the presence of the low activity communication signal.

Description

METHOD AND DEVICE FOR ESTABLISHING TDD / TTI SERVICE, ON VOCALALLY CODED CHANNELS BACKGROUND OF THE INVENTION 1. Field of the Invention In general, the present invention relates to the field of telecommunications devices for the deaf (TDD). More particularly, the invention relates to the negotiation of service within a telecommunication system that allows a signal passed in a low activity code to be transmitted by the system. The system can include wireless links. 2. Description of Related Art Many deaf or hearing impaired use communication terminals built and designed specifically to allow them to communicate over standard telephone lines. Such devices, known as the Telecommunication Device for the Deaf (TDD) or Textual Telephone Audience (TYY), are collectively referred to as TTD in this application. Typically, TDDs include a keyboard and a display device connected to a telephone via a modem (modulator / demodulator). The modem is integrated into the TDD and is directly connected to a telephone line or coupled by an acoustic coupler to a normal telephone set. TDDs are capable of transmitting information over telephone lines by means of coded tones to other TDDs connected at opposite ends of the telephone line through another modem. These tones are known as low activity communications because the envelopes of frequency and amplitude remain relatively constant. The code and protocol that are widely used in conventional use used for TDD communications are idiosyncratic. The set of codes, known as Baudot, and the communication protocol (TDD protocol) evolved historically at a time when many telecommunication devices for the deaf were based on mechanical or electromechanical devices instead of electronic devices. Consequently, the TDD protocol was built for a set of constraints that are no longer relevant to current devices. Those restrictions work to create a code protocol and a telecommunication network of users and devices that operate under that protocol, which is somewhat outdated.

Traditionally, TDD communications were conducted at 50 Baud (45.5 Baud in some countries), which represents a transfer of 6 characters per second. Other protocols now available for TDD communications incorporate higher Baud rates, such as the improved ASCII (Information Exchange in American Standard Code) and Baudot protocols. Regardless, a set of normal TDD communication characters consists of characters that are 5 bits in length. These characters are analogous to a letter e an alphabet, where each letter represents a word or idea. A character is grouped with some bits of information before the transfer, where each group of bits to be transferred has a duration of a unit interval equal to 20 milliseconds. For example, under the conventional TDD protocol, a group of bits to be transferred comprises 8 bits: an initial bit (a source or zero bit), five bits that represent the character, and at least one and 1/2 bits that mark the stop point of the transfer group. Compared to modern telecommunication systems, TDD transmissions occur at a snail's pace. A major problem is that the TDD signals are substantially constant. These monotonic, slow-moving signals can create havoc in digital telecommunication systems that transmit higher-activity signals at very high speeds, and especially in telecommunication systems that include wireless links. An example of such a communication system is a code division multiple access (CDMA) system, which has a large number of wireless subscriber units. Each subscriber unit has a transceiver and communicates with the system through satellite repeaters or terrestrial stations known as cells. Each cell includes a physical plant called a base station. A cell covers a limited geographical area and routes calls carried on subscriber units to and from the telecommunications network via a mobile switching center. When a subscriber moves into the geographical area of a new cell, the routing of that call of the subscriber can be done eventually through a new cell by a process called "transfer". A subscriber unit, referred to generically as a cellular telephone, transmits a signal that is received by a base station. The signal is retransmitted to a mobile switching center that routes the signal to a public switched telephone network (PSTN) that includes telephone lines or other subscriber units. Similarly, a signal can be transmitted from the PSTN to a subscriber unit via a base station in a mobile switching center. The interface or interconnection between the subscriber unit and the base station is known as the interface or aerial interconnection. The Telecommunications Industry Association (TIA) has provided a standard for the processing of CDMA calls over the interface or aerial interconnection entitled "IS-95 Mobile Station - Compatibility Standard for the Base Station for Extended Bandwidth Cell System Wide Double Mode ". The appendices to IS-95 are provided as Telecommunications Service Bulletins (TSB). The IS-95 + TSB74 standard includes provisions for the negotiation of service over the interface or aerial interconnection and is incorporated herein by reference. Service negotiation is critical to successfully transmit any communication, especially a low activity TDD communication, over a digital telecommunication system. One problem with modern systems, including those described above, is that a vocoder - a device used in the system to encode an analog voice signal or TDD in a digital signal, and to decode a digital signal in an analog voice signal or TDD - has difficulties in handling a substantially monotonic signal and low speed dictated by the TDD protocol. In addition, there is currently no method or device to notify a system | of telecommunication that is receiving a TDD communication and that makes the adjustments that are required to successfully transmit a signal of low activity. In current systems, a low-activity communication signal such as a TDD communication would likely be treated by the vocoder as background noise or signal interference and would be discarded. What is needed is a method and apparatus that can be easily integrated into existing digital communication systems, that can detect when a low activity communication is being received, such as a TDD communication, and that can notify the system to negotiate automatically the service to be used by the communication system during the transmission of the low activity communication. The method and device should be compatible with, CDMA modulation systems and the techniques used in telecommunication systems that service large numbers of system users. A more robust discussion of those CDMA systems and techniques in this type of multiple access communication systems can be found in U.S. Patent No. 4,901,307, entitled "ACCESS COMMUNICATION SYSTEM MULTIPLE EXTENDED SPECTRUM THAT USES REPEATERS OF SATELLITE OR TERRESTRIALS ", granted to the beneficiary of the present invention is incorporated herein by reference.In addition, the method and device should also be compatible with other modulation systems and techniques used for communication systems, such as multiple division access schemes of time (TDMA), multiple access by frequency division (FDMA), and amplitude modulation (AM).

BRIEF DESCRIPTION OF THE INVENTION Broadly speaking, the present invention involves the determination of service in a telecommunication system that allows a low activity communication to be transmitted by a digital telecommunication system. More particularly, the invention relates to a method and apparatus that synchronize any voice coder and decoder (vocoder) involved in the transmission of low activity communication at full speed and notify the telecommunications system that incorporates the vocoder to reduce the minimum transmission frame error percentage (FER) by adjusting the transmission parameters of the system that are necessary.

One embodiment of the invention provides a method for establishing the service used to transmit a TDD communication within a telecommunication system. Although a TDD communication is discussed through this application, it should be understood that any slow or low activity communication may be transmitted and used in this invention. In this mode, after the TDD communication signal is received, each vocoder involved in the processing of the TDD signal is synchronized at full speed. At full speed, as discussed more fully below, it refers to representing a signal transmitted using a fixed number of unique bits. The TDD signal is coded to create a digital signal and then transmitted by the telecommunication system. In one embodiment, once the telecommunication system is notified that a TDD signal is being received, each vocoder is automatically synchronized at full speed, and where applicable, the system attempts to decrease the errors in the air link, such as by increasing the transmission power to reduce the FER. In addition, the telecommunication system can include any number of wireless links. In another embodiment, the invention can be implemented to provide a notifying apparatus to be used with a telecommunications system to transmit TDD communications. The notifying apparatus may include a device gate configured to receive a TDD add-on which allows a TDD keypad and monitor to be communicatively coupled to the telecommunication system. The device door may include an integral sensor that detects when a TDD device has been connected to the door and causes the telecommunication system to be notified that a TDD communication may be received. The invention provides its users with numerous advantages. An advantage is that a TDD message can be transmitted using a digital transmission medium that has wireless links. Another advantage is that when a TDD device is connected to a digital telecommunication system, the device can be "detected" automatically and the system can establish the service needed to transmit the TDD signal. A further advantage is that a TDD device can be connected to a mobile subscriber device or unit, such as a digital cellular telephone, connected to the telecommunications system by a wireless link. The invention also provides a number of other advantages and benefits that will become more apparent after reviewing the following detailed descriptions of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS Nature, objects and advantages of the invention will become more apparent to those skilled in the art after considering the following detailed description in connection with the accompanying drawings, in which like reference numbers designate similar parts therethrough, and where: FIGURE 1 is a block diagram of the physical components of computing and interconnections of the telecommunications system incorporating wireless links according to an embodiment of the invention; FIGURE 2 illustrates a typical TDD communication device of the prior art, used in accordance with one embodiment of the invention; FIGURE 3 shows a notifying apparatus and a low activity device attachment according to one embodiment of the invention; and FIGURE 4 is a block diagram of one aspect of the method according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES FIGURES 1 through 4 illustrate examples of various aspects of the method and apparatus of the present invention. To facilitate the explanation, without any limitation being intended, these examples are described in the context of a TDD communication device connected to a digital telecommunication system incorporating wireless links, an example of which is described below.

PHYSICAL COMPONENTS OF COMPUTING AND INTERCONNECTIONS FIGURE 1 illustrates a type of telecommunications system 100 that includes wireless links and a TDD communication device (TDD) 200 as used in the present invention. As shown in detail in FIGURE 2, TDDs usually include a keyboard and a display that are connected to a telephone via a modem (modulator / demodulator). The modem is integrated into the TDD and is directly connected to a telephone line or coupled by an acoustic coupler to a normal telephone set. The TDDs are capable of transmitting information over telephone lines by means of coded tones or other TDDs, such as the TDD 102 shown in FIGURE 1, connected to the opposite ends of a telephone line through another modem. In digital telecommunications systems using wireless links, the TDD 20 can be coupled to a subscriber unit 104 which is used in the telecommunications system 100 to transmit the received signals. Exemplary embodiments of a mobile unit 104 are digital signal telephones, such as the Q-800 manufactured by QualComm, Inc., and commonly referred to as cell phones. The subscriber unit 104 as shown in FIGURE 1 includes a notifying apparatus 106 communicatively coupled to the circuits of the subscriber unit 104 and commonly known to those skilled in the art. Physical computing components 108 may be used to connect the TDD 200 to the subscriber unit 104 via the notification apparatus 106. In one embodiment, the notification apparatus 106 includes a device door 300 as shown in FIGURE 3. The door of the device 300 can be configured to receive an attachment of a low activity communication device 302 such as a plug, connector, receiver. These items are commonly used today to connect telephones and computer equipment, and are readily available from electronic device distributors. The door of the device 300 is interconnected with an attachment 302 to communicatively connect a low activity communication device (not shown) such as from the TDD 200 to the subscriber unit 104 of the telecommunications system 100. The door of the device 300 allows exchanging information between a low activity communication device and the subscriber unit 104. A sensor 304 can be included in the door of the device 300. The sensor 304 cooperates with the door of the device 300 to detect when a device has been connected or disconnected. of low activity communication to the subscriber unit 104, or when a low activity communication signal has been received or has been terminated. This detection causes the vocoders used by the telecommunication system 100 to be notified that a low activity communication will be received or has been terminated. If reception was reported, any vocoder used to transmit the low activity communication signal is synchronized at full speed. In another modality, the vocoders are synchronized at full speed and the transmission power used to transmit the low activity signal is adjusted as necessary to decrease the percentage of frame errors (FER) and improve the quality of the transmission. Usually, the transmission power is increased by the system in an attempt to achieve a desired FER. If notification is received that the low activity communication has ended, the vocoders are desynchronized and re assume their regular functions. This response by the vocoders is discussed in more detail later. The sensor 304 may simply comprise a pin or terminal 106 and a contact 308. When the attachment 302 is inserted into the door of the device 300, the pin or terminal 306 is depressed and comes into contact with the contact 308. This contact may close a circuit thus allowing the insertion of the attachment 302 to be detected. A variety of circuit designs for this type of detection arrangement are known in the prior art and can be used. In another embodiment, the sensor 304 may comprise a light beam or laser with continuity detector, the beam being interrupted when the door device 302 has been inserted and the initial interruption of the notification signal. In another embodiment, the sensor may comprise programs and programming systems and associated physical computing components, such as a processor, which detects when a low activity communication signal is received or terminated by the door of the device 300 and communicated to the unit Subscriber 104. Regardless of the mode, sensor 304 causes the notification that a low activity communication signal has been received for transmission or if it has been completed, is sent to the telecommunications system 100. As shown in FIGURE 3, the door of the device 00 may include walls 310, where the walls form an open enclosure at the end and define a recess 312. The communication connectors (not shown) may be coupled to at least one wall 310 and extend into the recess 312, where the connectors are configured to receive the low activity communication device 200. A communication link 314 of a variety known in the art is coupled to the communication connectors to the telecommunications system, where the The low activity addressee receiver 302 at the door of the device 300 allows a communication signal of the low activity communication device to be received by the telecommunications system 100. Returning to FIGURE 1, after the low communication signal activity is received by the notifying apparatus 106, the signal is processed by the subscriber unit 104. In a basic way, it is c It outputs a transmission signal that includes the information contained in the low activity signal. Because the telecommunications system 10 has been notified that a signal of low activity is being transmitted, the system is adapted to ensure that a decipherable transmission occurs. For example, an analog signal received from the analog circuit 228 shown in FIGURE 2 would normally experience a signal processing or "voice" that includes digitizing the signal, establishing a transmission power level to protect against fading of the signal during transmission , signal compression, and filtering. These functions can be performed by the circuits (not shown) of the subscriber unit 104 and include a vocoder. Depending on the received signal, the vocoder dynamically determines and negotiates the service within the telecommunications system 100 to provide a successful transmission and decode the signal. This negotiation involves establishing the values for multiple parameters, such as the speed that the vocoder should use, the transmission power and the compression technique. A more complete discussion concerning the processing of the signals for transmission in the telecommunication system can be found in the Electronic ISO Association Standard TIA / EIA / IS-95-A entitled "Station-Based Station Compatibility Standard. Mobile for Extended-Spectrum Wideband Dual-Spectrum Cell Systems "incorporated herein by reference, and other transmission standards well known in the art. Nevertheless, when the low activity signal is received, a vocoder can identify the signal as noise, a pause, or a signal that is not intended to be transmitted. Simply, a vocoder does not know which service to use because it can not identify the signal of low activity received. By notifying the system 100 that a signal of low activity is being sent, the vocoder will establish the necessary service to ensure the best possible transmission and decoding of the signal. In one modality, this service negotiation results in the vocoders being synchronized at full speed. Additionally, the level of transmission power may be increased, or at least not reduced, thereby reducing the percentage of frame errors that might otherwise make the transmitted signal indecipherable. This decrease in the FER can be caused by a closed circuit power control system included in the communication system that automatically increases the power to less than FER. After the low activity communication signal has been processed and the service completed, a digitized signal can be transmitted using an antenna 112 over a wireless link 114. The digitized signal is received by an antenna 116 at a remote location, such as the base station 118, processed by the base station circuit (not shown) which includes a vocoder 120. The different base station circuit arrangements for the communications systems are well known in the art, and a better understanding can be found in TIA / EIA / IS-95-A to which reference was made above. By processing the signal after reception, a low activity signal may be released that reflects the activity contained in the low activity signal transmitted to the low activity device 102 via the communication link 120. A second reporting device 106 is shown coupled to the base station 106. This is provided for a low activity signal to be sent from the low activity communication device 102 back to the TDD 200 communication device.

The communication link 120 appears bifurcated to emphasize that the base station 118 may not be directly connected to the low activity device 102. The base station 118 is usually connected to a standard PSTN switching station commonly used by telephone companies for the coordination of the telephone calls and the low activity device 102 is connected to the PSTN. In another embodiment, a mobile station signal (not shown) connected to the low activity communication device 102 can be linked to the base station 118. In addition, a telecommunication system can include mobile switching stations as mentioned above. Shown in FIGURE 2 is a schematic block diagram of the circuits of a typical TDD device 200, TDD either standard or enhanced, which operates with the present invention. In the TD 200 device of FIGURE 2, a keyboard 202 is provided on which the user can mount data characters. The output of the keyboard 202 is connected to a processor 204 which serves to control the elements of the circuits contained in FIGURE 2. The characters that are received or transmitted by the processor 204 are also presented in a visual representation device 206. Optionally, the same received or transmitted characters can be produced on a device such as a printer 208. Some TDD devices can not have a printer, although it is standard for TDDs to have a visual representation device of some type, so that a user can see the characters that are being written and received. The keyboard 202 in this way functions as a data character feed source to the processor 204, while either or both of the display device 206 and the printer 208 serve as local destinations for the characters of the data stream. The processor 204 can be connected by suitable data and address channels that would typically be used for this type of application by one skilled in the art. In FIGURE 2, the channel 210 connects a read-only memory (ROM) 212 to a non-volatile random access memory (NVRAM) 214. The appropriate control lines 216 and 218 are connected from the processor 204 to the RAM 212 and the NVRAM 214 provides interactive control of those units. The RAM 212 is intended to permanently store the program that dictates the operation of the processor 204 as well as certain data used by the program. For example, you can store ordered sequences of special characters for machine-to-machine communication to synchronize two TDDs in an enhanced mode of operation. NVRAM 214 is used as a buffer, a floating storage unit for data entering or leaving the TDD device, and for storing standard messages entered by the user through user 202 and intended to be stored. be quick They can be used; other circuit configurations, such as the configuration of the microprocessor 202 with the RAM 212 and the NVRAM 214 in a single integrated circuit. Also connected to the processor 202 in FIGURE 2 is a telephone numeric keypad 220 which allows entering telephone numbers by dialing through the processor 202 through the telecommunications system 100. A standard telephone device 224 rests on a hook of the switch 226 incorporating a switch (not shown) that indicates whether the telephone set 224 is in use and is thus removed from the hook of the switch 226. The processor 204 is communicatively connected through the analog circuit 228 to the telecommunications system 100. This connection is shown as a wired connection 230, but can be any type of connection that can communicatively link the analog circuit 228 with the telecommunications system 100. The analog circuit 228 provides a connection between the telephone set and the processor 202 which allows both Baudot tones and dial tones to be received by the telecommunications system 100. The analog circuit 228 provides an interface or interconnection of voice information to and from the apparatus telephone 224. The analog circuit 228 of the TDD device 200 is connected to the telecommunication system 100 using a connector such as the device discussed in relation to FIGS. 1 and 3. Despite the above specific descriptions, those skilled in the art have the benefit that this description will recognize that the apparatus described above can be implemented in a telecommunications system of different construction without departing from the scope of the present invention. As a specific example, the multiple subscriber unit 104 may be linked to the base station 118, or the low activity communication device 200 may be integrated with the subscriber unit 104.

OPERATION Several aspects of the methods of the present invention were described above. To facilitate and better understand the invention, FIGURE 4 shows a flow diagram of a method of the invention. The method starts at task 402, where the low activity ce signal is received by the telecommunications system. After the signal is received, the vocoders used by the system during signal processing are synchronized at full speed in task 404. In this mode, the transmission power can be increased but not decreased by a reference transmission power; that is, it does not decrease from the transmission power used by the telecommunication system for full-speed transmissions in task 410. Typically, the vocoders will be synchronized at full speed and the transmission power will be increased to transmit low activity signals. , At full speed refers to the fact that each bit contained in each frame of a signal represents a single bit of information. At half speed it refers to sending the same number of bits per frame, however each bit that appears is repeated once in the frame; that is, each bit of information will appear twice in a table. A quarter of a speed refers to each single bit that appears four times per frame, and so on. As, a bit of information is repeatedly sent, less the total information sent per frame. At full speed the signal is sent to a higher power because a given bit is sent only once. This full-speed power level is referred to as the reference power for the purposes of this application. Because the bits are repeated at lower speeds, a reduced power level is used because 1 power for every bit distributed is accumulated on the frame. The power level is typically set based on an FER selected by the signal transmitted as received at a remote location, also referred to as the target of the transmitted signal, such as the subscriber unit. A desired FER is selected because when a low activity signal is being sent, the actual FER is increased. This range of selected FER is between a percentage of errors of 0.1% and 1.0%, but may be higher or lower if necessary for the preservation of the quality of the transmitted signal. Preferably, a 0.2% FER is desirable for low activity signals. If the FER exceeds the range selected in task 412, the remote location notifies the transmission station conveniently in task 406, such as the base station 118, shown in FIGURE 1, that a system adjustment is necessary to reduce the FER and an adjustment is made in the task 408. An adjustment will typically include increasing the transmission power of the full-speed transmission, but may also include adjusting other known parameters to reduce the FER. If the FER is acceptable in task 412, signal transmission can continue in task 414 and dynamic adjustments to the telecommunications system continue through the transmission of the entire transmitted signal 410. Otherwise, when the transmission of the low activity signal ends, the vocoders are desynchronized, and the telecommunications system returns to normal operation. In other words, the desired FER is increased to the previous level. The adjustment of vocoders at full speed for the transmission of a low activity signal does not prevent other types of transmissions from occurring on the telecommunications system. The voice signals and data signals can transmit at full speed, or the telecommunications system can go back and forth between the full-speed transmission of low-activity communications and transmissions at other speeds and power levels.

OTHER MODALITIES Although what has been shown so far is considered the preferred embodiments of the invention, it will be evident to those skilled in the art that various changes and modifications can be made without departing from the scope of the invention as defined by the claims. annexes. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (7)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property.
2. A method for determining the service used in a telecommunications system to transmit a low activity signal, characterized in that it comprises: receiving the low activity communication signal; synchronize all the vapors synchronized in the processing of the communication signal of low activity at full speed; encode the low activity communication signal to create a digital signal; adjust the system if necessary to maintain a minimum target frame error rate for the low activity signal; and transmit the digital signal. (2) The method according to claim 1, characterized in that it further comprises: notifying all the vocoders used in coding and decoding of the low activity communication signal that the low activity communication signal was received, and where the synchronization of the vocoders occurs automatically as a result of the notification, and where the error rate of the maximum objective frame is between an error percentage of 0.1% and 1.0% 3.
3. The method according to claim 1, characterized in that the transmission is a remote location connected within the telecommunications system by the wireless link ..
4. The method according to claim 3, characterized in that it further comprises: notifying all the vocoders used in the coding and decoding of the low activity communication signal. that a low-activity communication signal will be transmitted, and where the synchronization of all vocoders occurs automatically as a result of such notification.
5. 5. The method according to claim 4, characterized in that the notification comprises sending a notification signal to the vocoders.
6. 6. The method according to claim 5, characterized in that the notification signal is not included in the low activity communication signal.
7. 7. The method according to claim 6, characterized in that it further comprises detecting a low activity telephone modem connected to a telecommunications system, where the notification is caused by such detection. The method according to claim 6, characterized in that it further comprises: receiving the digital signal at the remote location; and decoding the digital signal to recreate a low activity communication signal, where the recreated low activity communication signal communicates the same information as the digital signal when it is transmitted. The method according to claim 8, characterized in that it further comprises maintaining or increasing the transmission power to maintain a maximum objective frame error percentage for the digital signal. 10. The method according to claim 8, characterized in that it also comprises desynchronizing the vocoders at full speed. The method according to claim 9, characterized in that it comprises notifying the vocoders in the telecommunications system used to transmit the low activity communication signal that the low activity signal has ended, where the desynchronization of the vocoders occurs automatically as a result 'of the notification. 12. The method according to claim 1, characterized in that it further comprises' notifying the vocoders in the telecommunications system used to transmit the low activity communication signal that another speed communication signal has been received, where the desynchronization of all vocoders occurs automatically as a result of the i other speed notification. 13. The method according to claim 9, characterized in that the error rate of the target frame is between 0.1% and 1.0%. 14. The method according to claim 9, characterized in that the percentage of objective frame error is 0.2%. 15. A notifying apparatus used in a telecommunications system used to transmit the low-activity communication signal, characterized in that it comprises: a device door, the door of the device configured to receive an attachment of the low-activity device, the door is interconnected with the attachment to connect communicatively the low activity device to the telecommunications system; and a sensor integrated into the door of the device, the sensor detects that the low-speed communication device has been connected to the telecommunications system, the detection causes the telecommunications system to be notified that a low-activity telecommunication will be received, such notification results in the vocoders used to transmit the low activity signal being synchronized at full speed. The apparatus according to claim 15, characterized in that the door of the device further comprises: at least one wall, at least one wall forms an open space at one end and surrounds a hollow interior; communication connectors coupled to at least one wall and extending towards the gap, where the connectors are configured to receive an attachment of a low activity device connected to the low activity communication device; and a communication link that couples the communication connectors to the telecommunications system, where the reception of the low activity device attachment at the door of the device allows a communication signal of the low activity communication device to be received by the communication system. telecommunications The apparatus according to claim 16, characterized in that the sensor comprises a tang or terminal coupled to at least one wall and extending towards the recess, where the spigot or protrusion moves when the attachment of the low activity communication device is received by the door of the device, the deflection produces the notification to the telecommunication system that a communication of low activity will be received. The apparatus according to claim 16, characterized in that the sensor comprises a digital device configured to detect when the communication connectors receive a communication signal of low activity. 19. A notifying apparatus used in a telecommunications system for transmitting a low-activity communication signal, characterized in that it comprises: door means for interconnecting, an attachment of a low-activity communication device for communicatively connecting a communication device of low activity to the telecommunications system, the door means are configured to receive the attachment of the low activity telecommunication device; sensor means coupled to the door means for detecting when a communication of low activity has been communicatively connected to the telecommunications system and for causing the telecommunications system to be notified that it will receive a communication of low activity. 20. The apparatus according to claim 19, characterized in that the notification to the telecommunications system causes any vocoder involved in the transmission of such low activity communication to be synchronized automatically at full speed, and where the telecommunications system makes the necessary adjustments to minimize any percentage of objective frame error experienced during transmission. 21. The apparatus according to claim 20, characterized in that the percentage of objective frame error is between an error rate of between 0.1% and 1.0%. 22. The apparatus according to claim 20, characterized in that the target frame error percentage is 0.