Mobile Frequency Range Rx: 869-894; Tx 824-849 Multiple Access Method FDM Duplex Method FDD Number of Channels 832 Channel Spacing 30kHz Modulation FM AMPS AMPS (Advanced Mobile Phone Service) was the first cellular mobile system in the United States. AMPS operates as an analog system using 30 kHz wide channels. NAMPS AMPS was later enhanced …
A 66 block is a punch-down block used to connect wiring for telephone systems and other low-speed low-voltage wiring applications. A punch-down tool is used to force solid wire into metal slots on the 66 block. The 25-pair standard non-split 66 Block encloses 50 rows; each row has four columns of clips that are electrically …
SS7 (Signaling System 7) is a standard for control signaling in the PSTN (Public Switched Telephone Network. SS7 signaling is done out-of-band, meaning that SS7 signaling messages are transported over a separate data connection. This represents a significant security improvement over earlier systems which used in-band signaling. The first CCS protocol was the Signaling System …
Blocking incoming calls can sometimes be quite important for many reasons. Someone may be troubling you over the phone, harassing you, giving blank calls and you just want to avoid a specific person. A simple way to do this is to block an incoming call of a specific person. That is, whenever that person calls …
Anyone who has conducted or participated in a telephone conference call knows how noise can interrupt the meeting. There are a number of ways to prevent some types of noise from ever occurring, as well as ways to quickly eliminate noise if it does occur during a call. Before the Call Most noise issues on …
A “Milliwatt (102 Type) Test Line” is a signal generated from an Access Service Provider end office to the customer’s location for the purposes of transmission measurement, that is, testing the line quality and loss of transmission. The generated signal is a 1004 Hz tone at 0 dBm, which is the equivalent of 1 milliwatt …
DSN stands for the Defense Switched Network which is a global phone service used by the United States government capable of both non-secure and secure communications. Traditionally, the DSN network has only been used for voice communications, but in the past decade data and video service have been incorporated into the network through Integrated Services …
CNAM (“Calling NAMe”) is an Intelligent Network (IN) service that displays a caller’s name on a digital readout. It is very similar to caller ID except that both the caller’s name and the calling number are displayed on the receiving end of the phone call. This feature only works if the person or organization being …
The telephone Network Interface Device (NID) is what connects your home telephone lines to the telephone company’s network. It is usually a small gray box located on the exterior of your home. It usually contains a modular phone plug that you can use for testing the line. They need both inside testing and outside testing. …
When dealing with a wet phone, it is important to act quickly. Few phone companies offer a warranty on wet phones and have gone as far as to place a "wet strip" on the phone that changes colors when it has gotten wet. What this means is that the wet strip will allow the company …