Forward and reverse channels refer to a number of frequencies that are used by a telecommunications broadcast system in order for a telephone tower and a cellular telephone to communicate with each other. A forward channel refers to the frequencies used by a telephone tower to communicate with all nearby cellular phones. Contrastingly, a reverse channel refers to the frequencies used by cellular telephones to communicate with a telephone tower.   How Forward and Reverse Channels Work While some companies may depend on different telephone systems, most rely on the Read More

Many telephone companies maintain telephone numbers which will temporarily disconnect telephone service for testing. If your NPA is not listed, or the listing does not cover your LATA, try common numbers such as 119 (GTD5 switches) or 511. NPA Telephone Number Geography Length of disconnection 209 999 Stockton, Fresno, Lodi, CA 100 seconds 281 325 Houston, TX 3 minutes 313 xxx-9994 Ann Arbor, Dearborn, Detroit, MI (Ameritech) 1 minute 314 511 Columbia, Jefferson City, St.Louis, MO 1 minute 404 420 Atlanta, GA 5 minutes 405 953 Enid, Oklahoma City, OK Read More

Telephone switches route calls through the PSTN (Public Switched Telephone Network). When you pick up the handset on your home telephone, you are initiating a connection with your local telephone switch. When you dial a telephone number, your phone switch interprets the digits you dial and determines where to route your call. If your call is to another number in the same area, your local end-office switch will make the call itself. If your call is to another area, your local end-office switch will route your call to a toll-switch. Read More

What is Ground Start? Ground Start or GST is a signaling technique for telephony from a terminal, or a subscriber local loop, to a telephone exchange in which a party gets a dial tone by momentarily grounding one side of a (telephone) circuit. The Ring side of a wire pair is usually the side that is grounded. Local telephone companies typically provide two types of dial tone switched trunks — ground start and loop start. Most pay-phones use ground start signaling. Ground Start vs. Loop Start Loop start is the Read More

GSM (Global System for Mobile communication) is a digital mobile telephone system that is widely used in Europe and other parts of the world. GSM uses a variation of Time Division Multiple Access (TDMA) and is the most widely used of the three digital wireless telephone technologies (TDMA, GSM, and CDMA). GSM digitizes and compresses data, then sends it down a channel with two other streams of user data, each in its own time slot. It operates at either the 900 MHz or 1,800 MHz frequency band. GSM is the Read More

A BlackBerry is a popular mobile phone that Research in Motion (RIM) produced. It is able to send and receive email, download and update calendars, and make phone calls. Unlike other phones, the BlackBerry comes with a complete, alphanumeric keypad in order to support the email function that has made the phone so popular in business and academic circles. How Does a BlackBerry Receive Email? BlackBerry phones typically receive email via the BlackBerry Exchange mail service. The BlackBerry redirector checks the email account and forwards it to the BlackBerry device Read More

A TIMSI, or Temporary International Mobile Subscriber Identity, number is a random number that is created from a telecommunications subscriber’s IMSI number in order to provide additional security. While an IMSI is unique to each subscriber and is a permanent number that can be used to track a subscriber or interfere with his/her services, a TIMSI is often re-negotiated by the telecommunications company the subscriber is associated with and can only be stolen if an eavesdropper intercepts the initial GSM transmission when the TIMSI is negotiated.   How TIMSI Works Read More

The Blackberry Storm is an affordable touch screen smartphone that has several capabilities. In order to fully use all of the phone’s features, it is recommended that the user connects to a service network that provides a data plan and traditional phone services such as calling and texting. Blackberry Storm users can also customize their phones as it offers different color themes, wallpapers, and many other options for personalizing the phone. The Blackberry Storm has about a 5.5 hour talk life or 360 hours of standby. It gives average users Read More

A 110 block is a punch-down block used to connect wiring for telephone systems, data network wiring, and other low-voltage wiring applications. It improves on the 66 block by supporting higher frequencies and using space more efficiently. A punch-down tool is used to force solid wire into metal slots on the 110 block. Present residences typically have phone lines entering the house to a sole 110 block, and then it is spread by on-premises wiring to outlet boxes all over the house in a star topology. Sometimes due to over Read More

Blackberry users may come across a Java Virtual Machine (JVM) error that is known as the JVM 102 error. When this is displayed, it means that there is an invalid code in the phone’s file system. This error may also indicate that one or more .cod files have become corrupted or are now incompatible with the mobile phone. Unfortunately, the Blackberry is unusable until the error is corrected. Although the Blackberry Corporation advises its customers to slick the phone and restore the operating system (OS) to fix this error, there Read More