IEEE 802.20 was an IEEE standard developed by the Institute of Electrical and Electronics Engineers (IEEE) for Mobile Broadband Wireless Access (MBWA). It was formally known as "Standard for Mobile Broadband Wireless Access Systems."
Purpose and Goals The primary goal of IEEE 802.20 was to define an IP-based, high-speed wireless data standard specifically designed for high-mobility environments. It aimed to provide broadband internet access to users moving at speeds up to 250 km/h (155 mph), offering a "mobile DSL" experience. This included support for seamless handovers between base stations, low latency, and efficient use of licensed frequency spectrum.
Key Features and Technology IEEE 802.20 was designed with several advanced wireless technologies:
- Orthogonal Frequency-Division Multiple Access (OFDMA): This multiplexing scheme was used to efficiently allocate spectrum and provide robust performance in multipath fading environments, which are common in mobile scenarios.
- Multiple-Input Multiple-Output (MIMO): MIMO antenna technology was supported to enhance spectral efficiency and increase data throughput by utilizing multiple antennas at both the transmitter and receiver.
- Fast Handover: The standard emphasized rapid and seamless handovers between cells to maintain connectivity for users in high-speed mobility scenarios.
- Licensed Bands: It was designed to operate in licensed frequency bands below 3.5 GHz, which allowed for better interference control and more predictable performance compared to unlicensed spectrum.
- Packet-switched IP connectivity: The entire system was designed around delivering IP-based data services.
Context and Competition IEEE 802.20 emerged during a period of intense innovation in mobile wireless communication, positioning itself as an alternative or complementary technology to other standards:
- IEEE 802.16e (Mobile WiMAX): Both standards aimed at mobile broadband, but 802.20 focused more heavily on high mobility and lower latency, often targeting different frequency bands and deployment models.
- 3GPP Technologies (UMTS, HSPA, LTE): As 3G (UMTS/HSPA) evolved towards 4G (LTE), 802.20 faced strong competition from established cellular ecosystems with vast global deployment and device support.
Status and Legacy Despite its technical merits and ambitious goals, IEEE 802.20 did not achieve widespread commercial deployment. The development process was protracted, facing challenges related to internal disputes and the rapidly evolving mobile broadband landscape. Ultimately, technologies like Mobile WiMAX (802.16e) and particularly Long Term Evolution (LTE) from 3GPP gained significant market traction and became the dominant 4G mobile broadband standards.
The IEEE 802.20 working group was eventually disbanded, and the standard was officially withdrawn by the IEEE. While it did not succeed commercially, the concepts and technical approaches explored within 802.20 contributed to the broader body of knowledge in mobile broadband system design and helped inform subsequent wireless standards.