Rainbow broadband

Technology

RAINBOW BROADBAND CARRIER CLASS HYBRID FIBER MICROWAVE NETWORK

CONTRIBUTORS: Russ Hamm, Andrian Lubimov, Jimi Whalen, Mark Albanese and John Koruth.

CORE NETWORK

Rainbow built its network using a combination of fiber rings and microwave radios. We call it a HYBRID FIBER MICROWAVE NETWORK (HFM).Our distribution hubs are located on the roofs of buildings with good line-of-site to other commercial office buildings, but not necessarily the tallest building. We have a dozen strategically located distribution hubs in New York with line of site to over 1,000 commercial buildings. We continue to expand the number of hubs to provide coverage for more buildings. Fiber rings connect our hub sites to the major Carrier Hotels where we connect to CLECs, our Service Providers, the “Cloud” and to the Internet. We use microwave radios to beam broadband connections from our distribution hub sites to commercial buildings. We connect our customers within a building to a central Demarcation point by running cabling through the building’s risers. Rainbow’s Ethernet/MPLS Core Network complies with Metro Ethernet Forum standards 6.1. and 10.1

Network core architecture consists of dual fiber rings connecting major data centers and distribution HUBs. At the Interconnect Sites ENNI cross connections hand off traffic to Carriers, Service Providers, VoIP Providers and to multiple Tier One Networks. ENNI - Cross connections to carriers and service providers are 100 Base-T or 1000 Base-T. Our locations: 111 Eighth Avenue, 14^th floor Telx, 60 Hudson Street, 9^th floor, Telx, 32 Avenue of Americas, 24^th floor, Rudin Management.

MICROWAVE LINKS

We use point-to-point microwave links to connect customers to our distribution hub locations. We have many years of expertise in microwave engineering. We are able to provide highly reliable microwave service that is not affected by weather conditions such as rain, snow or ice. These links are not just for data transport, they also deliver our high quality voice service. This is a unique capability. Our competitors cannot reliably deliver voice services over their multi-point, microwave networks.

Antenna array at Rainbow distribution HUB showing point-to-point microwave links beaming service to customer buildings in a dense area of New York City.

Microwaves are widely used for point-to-point communications. AT&T pioneered the technology in 1947 with a link between New York and Boston. That grew to a communication network that carried the majority of long distance phone traffic for many years. Because of their small wavelength, high gain antennas can form very narrow beams connecting locations. This guarantees high reliability and allows reuse of the same frequencies without interfering with each other. The high frequency of microwaves also allows greater bandwidth for transmitting large amounts of information. A disadvantage is that microwaves are limited to line of sight propagation. New technologies like OFDM modulation and MIMO are making possible microwave links that can pass around certain obstacles like trees and buildings.

NOT SUCCEPTABLE TO RAIN FADE

Rain fade is the term for describing the absorption of microwaves by the atmosphere, rain, snow or ice. At frequencies greater than 10 GHz (Ku12 GHz), falling rain droplets can become a resonant multiple of the signal’s wave length. This effectively sucks energy from the signal causing fading.

Rain fade does NOT affect the frequencies below 6GHz (C Band) we use for our distribution links.

The wavelength of a C Band signal is approximately 60mm or 2.5 inches. That would be quite a large rain drop or even worse, a hail stone!