Browse Definitions :
Definition

simplex

Contributor(s): Stan Gibilisco

Simplex is a communications mode in which only one signal is transmitted, and it always goes in the same direction. The transmitter and the receiver operate on the same frequency. When two stations exist and they alternately (not simultaneously) send signals to each other on the same frequency, the mode is technically known as half duplex. However, most amateur radio operators refer to half duplex as simplex.

At high and microwave wireless frequencies, the simplex or half duplex modes will not provide enough communications range in some situations. To increase the effective range, wireless repeaters are used. In a typical repeater, the incoming signal has a different frequency than the outgoing signal, so that the transmitted signal does not overwhelm the repeater's receiver. Repeaters, strategically located in high places with large line-of-sight coverage zones, can greatly increase the range of a wireless communications system.

In order for a station to send and receive data simultaneously, two different frequencies must be used, one for transmitting and the other for receiving, a mode called full duplex. A more sophisticated mode called multiplexing allows for two or more signals or streams of information to be sent simultaneously in the same direction as an "interwoven" complex signal. The component signals are extracted and decoded individually at the receiving end.

The term simplex is sometimes used in reference to any program that resembles Simplex Database, a CGI (common gateway interface) script that provides a simple and portable database for Webmasters along with tools for creating custom Web apps.

This was last updated in August 2012

SearchCompliance

SearchSecurity

  • cyber attack

    A cyber attack is any attempt to gain unauthorized access to a computer, computing system or computer network with the intent to ...

  • backdoor (computing)

    A backdoor is a means to access a computer system or encrypted data that bypasses the system's customary security mechanisms.

  • post-quantum cryptography

    Post-quantum cryptography, also called quantum encryption, is the development of cryptographic systems for classical computers ...

SearchHealthIT

SearchDisasterRecovery

  • risk mitigation

    Risk mitigation is a strategy to prepare for and lessen the effects of threats faced by a business.

  • call tree

    A call tree is a layered hierarchical communication model that is used to notify specific individuals of an event and coordinate ...

  • Disaster Recovery as a Service (DRaaS)

    Disaster recovery as a service (DRaaS) is the replication and hosting of physical or virtual servers by a third party to provide ...

SearchStorage

  • cloud SLA (cloud service-level agreement)

    A cloud SLA (cloud service-level agreement) is an agreement between a cloud service provider and a customer that ensures a ...

  • NOR flash memory

    NOR flash memory is one of two types of non-volatile storage technologies.

  • RAM (Random Access Memory)

    RAM (Random Access Memory) is the hardware in a computing device where the operating system (OS), application programs and data ...

Close