Internet, Networking, & Security Home Networking What Is Multiple-In Multiple-Out (MIMO) Technology? MIMO is used in 802.11n and 802.11ac Wi-Fi networks Share Pin Email Print The Ultimate Router Buying Guide The Ultimate Router Buying Guide Introduction Router Basics What Is a Router and How Does It Work? How to Pick the Right Wireless Router Router Standards Explained Modem vs Router Can You Use Two Routers Same Network? Do I Need a Modem and a Router? Routers, Switches and Hubs Explained How to Find Your Router's IP Addresses What Is MIMO Technology? Best Names for Routers & Home Networks Best Placement for Wireless Routers How to Set up a Home Network Router Best Overall Routers Best Wireless Routers Best Cable Modem/Router Combos Best Long-Range Routers Best Secure Routers Best Parental Control Routers Best DD-WRT Routers Best Routers for Under $100 Best Routers for Under $50 Best 802.11ac Wi-Fi Wireless Routers Best 802.11n Routers Best 802.11g Wireless Broadband Routers Best VPN Routers Best Gaming Routers Best By Brand & Range Best Linksys Routers Best Wireless Router Brands Best Netgear Routers Best Routers at Walmart Top Routers Reviewed Google Wifi Review Netgear Orbi Review Netgear C3700 Review Netgear C3000 Review Linksys EA8300 Review Linksys EA9500 Review Linksys WRT3200ACM Review Samsung SmartThings Router Review Asus RT-AC88U Gaming Router Review Linksys AC1900 Review Best Router Essentials Best Wi-Fi Extenders Best Wi-Fi USB Adapters Best Cable Modems Best Powerline Network Adapters Best Surge Protectors By Bradley Mitchell Writer An MIT graduate who brings years of technical experience to articles on SEO, computers, and wireless networking. our editorial process LinkedIn Bradley Mitchell Updated November 27, 2019 42 42 people found this article helpful Multiple in, multiple out — pronounced "my-mo" and abbreviated as MIMO — is a method for the coordinated use of several radio antennas in wireless network communications. The standard is common in home broadband routers. How MIMO Works MIMO-based Wi-Fi routers use the same network protocols that conventional (single-antenna, non-MIMO) routers do. A MIMO router achieves higher performance by aggressively transmitting and receiving data across a Wi-Fi link. It organizes the network traffic that flows between Wi-Fi clients and the router into individual streams, transmits the streams in parallel, and enables the receiving device to re-assemble (reconstitute) the streams into single messages. Belkin N1 Wireless Router. belkin.com MIMO signaling technology can increase network bandwidth, range, and reliability at an increased risk of interfering with other wireless equipment. MIMO Technology in Wi-Fi Networks Wi-Fi incorporated MIMO technology as a standard beginning with 802.11n. MIMO enhances the performance and reach of Wi-Fi network connections compared to those with single-antenna routers. The specific number of antennas deployed in a MIMO Wi-Fi router varies. Typical MIMO routers contain three or four antennas instead of the single antenna that was standard in older wireless routers. Both a Wi-Fi client device and the Wi-Fi router must support MIMO for a connection between them to take advantage of this technology and realize the benefits. Manufacturer documentation for router models and client devices specify whether they are MIMO-capable. SU-MIMO and MU-MIMO The first generation of MIMO technology that was introduced with 802.11n supported single-user MIMO (SU-MIMO). Compared to basic MIMO, in which all the router antennas must be coordinated to communicate with one client device, SU-MIMO enables each antenna of a Wi-Fi router to be allocated separately to individual client devices. Multi-user MIMO technology (MU-MIMO) works on 5 GHz 802.11ac Wi-Fi networks. Whereas SU-MIMO requires routers to manage client connections serially, one client at a time, MU-MIMO antennas manage connections with several clients in parallel. MU-MIMO improves the performance of connections that are able to take advantage of it. Even when an 802.11ac router has the necessary hardware support (not all models do), other limitations of MU-MIMO also apply: It supports traffic in one direction: from the router to the client.It supports a limited number of simultaneous client connections (usually between two and four), depending on the router antenna configuration. MIMO in Cellular Networks MIMO technology is used in other kinds of wireless networks — for example, in cell networks (4G and 5G technology) — in several forms: Network MIMO or cooperative MIMO: Coordinates signaling among multiple base stations.Massive MIMO: Uses large numbers (hundreds) of antennas at a base station.Millimeter wave: Uses high-frequency bands where spectrum availability is larger than on bands licensed for use on 3G or 4G.