The case for Millimeter Wave Wireless

Corporations need higher bandwidth links among separate facilities on campuses and in urban areas. Service providers need affordable ways to provide them - rapidly.

Fiber links are expensive to deploy and are often not an option because of municipal or government restrictions or physical barriers such as waterways.

Microwave systems are difficult to license and don't offer  sufficient bandwidth to support the growth of high bandwidth applications.

Free space optics (FSO) systems are limited by fog, rain and other atmospheric conditions.

Millimeter wave wireless (MMW wireless or e-band wireless) is overcomes these challenges.

How MWW works

MMW wireless systems operate in the 71-76 and 81-86 GHz frequency bands under rules adopted by the European Telecommunications Standards Institute (ETSI) and the International Telecommunications Union (ITU).

This combined 10 GHz of spectrum is much larger than that for any other frequency allocation for cellular or microwave service. The availability of such a large swath of spectrum enables a whole new generation of wireless transmission systems.

MMW wireless enables full duplex Gigabit Ethernet or faster connectivity with carrier class availability over point-to-point links ranging up to 6km. With 5 GHz of bandwidth available per channel, it is likely that higher data rates will be accommodated as radio modulation schemes evolve in the coming years.

MMW has signal propagation characteristics comparable to those of common microwave bands, yet offers greater bandwidth in a narrower signal beam, minimizing the risk of interference and mitigating complex, time-consuming licensing procedures.

Advantages

When compared with terrestrial fiber, FSO and microwave technologies, millimeter wave wireless offers several advantages.

Cost - MMW wireless systems use cheap components. Unlike microwave, there is no need to compress the data into small frequency channels, so radio equipment can take advantage of low-order modulation modems, non-linear power amplifiers and other relatively simple wireless building blocks. This reduces cost and complexity.

Deployment simplicity - MMW wireless systems are small and light, typically using .3m or .6m parabolic antennas. With a beam width of less than one degree (compared with up to 11 degrees  for microwave signals), MMW wireless systems offer low risk of interference with other systems, and have simpler licensing procedures. In many cases, point-to-point links can be licensed and deployed within a few days, compared with weeks or months for fiber or microwave.

Reliability - unlike FSO systems, MMW wireless links are not disrupted by fog and can transmit with 99.999% reliability in all but the most severe weather conditions.

Bandwidth - currently, MMW wireless systems use a simple modulation scheme such as Binary Phase Shift Keying (BPSK), but with more spectrally-efficient modulation schemes under development, full duplex data rates of 10 Gbps could be realized within three years.

Frans Versluis, program manager, Network Solutions Business, ADC

[email protected]