2.Definition、Symbols and Abbreviations
Terminal Equipment: Equipment which is used in connecting to public switched telephone network for getting telephone communication service.
Loop Simulator: Simulated Circuit used in supplying DC loop current for testing.
Reference Load Impedance: A reference load impedance used in general test case of this technical requirement. 600Ωis used in general case, unless defined in special case of test. See Appendix.
Artificial Transmission Line: A simulated circuit used in test case to simulate the impedance and loss of telephone network.
Automatic dialing: Automatic dialing is defined asthe process whereby the dialing information is automatically transmitted after seizure of a line.
Automatic line seizure: Automatic line seizure refers to seizure of the line not immediately succeeding a manual operating procedure:
Automatic repeat call attempts : An automatic repeated call, of the same number that is failure at last call.
Call attempt:A procedure of TE in sending the call address number.
Communication state: The communication state commences after dialing, in the case of an outgoing call, or commences after answering of the call, in the case of an incoming call and ends with the transition of the terminal equipment to the quiescent state.
Connection to earth: A terminal of equipment used in connecting with Ground wire of power outlet or aconnection point on the equipment used in connecting to Ground while been test.
Dialing: Dialing begins with the emission of the first digit and ends with the last digit necessary for establishment of the call.
Dialing state: The dialing state is the operating state from the beginning to the end of the transmission of dialing information.
Inter-digital state: The inter-digital state commences on conclusion of the emission of one digit and ends when emission of the next digit commences or with the beginningof the communication states, as appropriate.
Longitudinal Conversion Loss: The measure of impedance is balanced to earth.
Network Termination Point (NTP): The physical connecting points to the Network.
Off hook condition:The off-hook condition commences when the terminal equipment has reached the stationary dc resistance level and ends with the transition to the dialing state or the quiescent state.
Operating states: The following operating states exist: quiescent state, off-hook condition, dialing state,inter-digital state, communication state, ringing state as well as the transitions to these states.
Quiescent state: The quiescent state is characterized by the fact that the terminal equipment is neither in a transient state nor in the dialing, ringing, off-hook, inter-digital or communication states.
Return Loss: Of the TE, a description of impedance is matching to PSTN.
Ringing state: The ringing state commences with the reception of the first ringing signal and ends with the answering of the call or when no further ringing signals are received.
Switching signals: Switching signals are electrical characters for signaling between terminal equipment and equipment of the telephone network.
Telecommunication messages: Telecommunication messages are electrical signals generated by terminal equipment and which are not required for communication with the telephone network.
Transient states: From the quiescent state to the off-hook condition of outgoing call, from the ringing state to the communication state incoming call or from the communication state to the quiescent state of call clearing.
Metallic voltage: The potential difference between the tip and ring connections.
Longitudinal voltage: One half of the vector sum of the potential difference between the tip connection and earth ground, and the ring connection and earth ground.
dBspl.:dB sound pressure level
a.c.: alternating current
dBm: dB miliwatt
dBV: dB Volt
DTMF: Dual Tone Multiple Frequency
ZR: Reference impedance
ERP:Ear Reference Point
MRP: Mouth Reference Point
r.m.s : root mean square
RL : Return Loss
ACTE:Automatic Call Transfer Equipment
DTMF:Dual Tone Multi-Frequency
HGP:DTMF High frequency Group Power
LGP:DTMF Low frequency Group Power
PBX:Private Branch Exchange system
PSTN:Public Switched Telephone Network
RVA:Recorded Voice Announcement