What Is Communication?

Communication, in the context of electrical and electronics engineering, is the transmission of information between two or more points using electrical, electromagnetic, or optical signals. It encompasses the design of systems that encode, modulate, transmit, receive, and decode signals across a medium, whether that medium is a copper wire, a fiber optic cable, a radio channel, or a satellite link. The field draws on signal processing, information theory, semiconductor device physics, and network architecture to create systems that move data reliably and efficiently across varying distances and conditions.

Shannon's 1948 paper "A Mathematical Theory of Communication," published in the Bell System Technical Journal, established the theoretical foundations that underpin all modern communication engineering: the concept of channel capacity, the relationship between bandwidth and signal-to-noise ratio, and the principle that redundancy can be used to overcome channel noise. Engineering practice in the field has since been organized around achieving communication rates as close to the Shannon limit as the hardware and latency budget of a given application permit.

Mobile Cellular Networks

Mobile cellular communication carries voice, data, and multimedia over radio links between handsets and base stations organized in a geographic cell pattern. Standards generations define the radio technology and network architecture used in each era. GSM (Global System for Mobile Communications), standardized by ETSI, established the 2G digital cellular framework using time-division multiple access (TDMA) and was first deployed commercially in Finland in 1991. CDMA (Code Division Multiple Access) provided an alternative 2G air interface. UMTS introduced 3G broadband mobile capability under the 3GPP standards body, supporting mobile data rates compatible with video streaming and internet browsing. Successive releases through 4G LTE and into 5G NR have continued to expand capacity using MIMO antennas, higher frequency bands, and more spectrally efficient modulation.

Base station infrastructure for GSM, EDGE, CDMA, UMTS, and 4G/5G systems constitutes one of the most capital-intensive segments of telecommunications networks, and the coexistence of multiple generations of equipment at a single site is a routine feature of cellular network management.

Broadband Access Technologies

Broadband access technologies deliver high-speed internet connectivity over the last mile between the service provider's network and the end user. Asymmetric Digital Subscriber Line (ADSL) transmits data over existing copper telephone lines by using frequency bands above the voice range, with downstream capacity exceeding upstream capacity, a design choice that matched the predominantly download-oriented usage patterns of early residential internet access. ADSL standards are defined by ITU-T Recommendations G.992.1 through G.992.5, with ADSL2+ supporting downstream rates up to 24 Mbit/s over short loops.

IEEE 802 standards cover complementary access technologies including Ethernet for wired local area networks and the 802.11 family for wireless LAN, both of which feed traffic into the DSL or cable access network on the way to the internet core. The interaction between access technologies, backhaul links, and core network capacity determines the end-to-end quality of service experienced by users.

Information and Communications Technology

Information and communications technology (ICT) is the broader term encompassing both computing infrastructure and communication networks as an integrated system. ICT includes the hardware, software, protocols, and services that enable storage, processing, and transmission of information. It spans enterprise computing, cloud infrastructure, mobile networks, and the internet, treating these not as separate domains but as components of a unified information infrastructure.

ICT investments have measurable effects on economic productivity, and the IEEE Communications Society covers the research and standards development that advance the field across wired, wireless, optical, and satellite communication domains.

Applications

Communication has applications in a range of fields, including:

• Mobile broadband services for consumer and enterprise internet access
• Formation control and coordination of autonomous vehicle and drone swarms
• Satellite and deep-space communication for scientific and commercial missions
• Industrial control systems and remote monitoring in manufacturing and utilities
• Emergency and public safety communication networks