Mobile cell sites are infrastructures transportable on trucks, allowing fast and easy installation in restricted spaces. Their use is strategic for the rapid expansion of cellular networks putting into service point-to-point radio connections as well as supporting sudden increases in mobile traffic in the case of extraordinary events (trade fairs, sports events, concerts, emergencies, catastrophic events, etc.). Mobile cell sites are also used by law enforcement organizations to gather intelligence. Mobile cell sites require neither civil works nor foundations, just minimal requirements like commercial power and grounding. The mobile units have been designed to be a temporary solution, but if requested, they can be transformed into permanent stations.
There are several different kinds of mobile cell sites, every one of which has different usage characteristics.
RDUs are mobile radio base stations transportable on trucks. Their use is strategic for the rapid expansion of cellular networks.
Cells on wheels (COW), or site on wheels,[1] are telecom infrastructures, placed on trailer approved for road use, towed by heavy goods vehicles for loads of up to 3500 kg. These mobile radio base stations guarantee full operation in just one day and in restricted spaces. COWs provide fully functional service, via vehicles such as trailers, vans and trucks, to areas affected by natural disaster or areas with large user volume, such as major events. The backhaul to the network can be via terrestrial microwave, communication satellite, or existing wired infrastructure.
COWs are used to provide expanded cellular network coverage and/or capacity for short-term demands, such as at special events such as major sporting events (Super Bowl, World Series, Rose Bowl), major conventions, or in disaster areas where cellular coverage either was minimal, never present (e.g., in a wilderness area where firefighters have set up a command center during a major forest fire) or was compromised by the disaster (e.g., in the Gulf Coast after Hurricane Katrina).
Following the September 11 attacks on New York City in 2001, 36 cellular COWs were deployed by September 14, 2001, in Lower Manhattan to support the U.S. Federal Emergency Management Agency (FEMA) and provide critical phone service to rescue and recovery workers.
COWs provided cellular service in Southwest Florida in the aftermath of Hurricane Charley in 2004 when most of the area's stationary cell towers were destroyed.[2] In January 2009, 26 cell-on-wheels units were put in place in Washington, D.C. for the inauguration of Barack Obama to handle the millions of extra people and their calls in the city, especially on and near the National Mall. In January 2017 additional COWs, both temporary, and permanent, have been installed at the National Mall for the inauguration of Donald Trump as well as for future inaugurations and other events due to the steady rise in LTE-based smartphones and other devices in the later half of the 2010s.
Many telecommunications companies also use COWs for long-term placement when financing or infrastructure considerations prevent building a permanent site at the location. For instance, a carrier may have approved the placement of a cell site for coverage reasons, but the remaining budget is inadequate to fund the construction for a fiscal quarter or even longer. An engineering team may be able to place a COW on location to provide immediate coverage with few costs other than leasing, electricity, and backhaul. The decision to use a COW for an extended period of time may also be driven by the property owner. Installations on government or military facilities may be granted only on a temporary basis and may require the use of non-permanent facilities.
A cell on truck is a particular kind of mobile cell site that is composed of mobile trucks with a container and with a self-mounting telescopic mast. They are portable structures that guarantee full operation in three hours and in restricted spaces. The steel interface frame is made of galvanized steel beams and is provided with four retracting stabilizers that can be retracted under the container for transport. The equipment and power container, which has a reinforced special 20' box container with two access doors, are divided by an intermediate partition to create two separate rooms (E and A). Room A is used for housing the electrical and radio equipment. Room E is used as a power room for housing the generating set and also, during transport, to contain the radiant systems and accessory components. The antenna supporting pole, with a standard height of up to 20 m, is made of aluminium and consists of three telescopic tubular elements. Installation is easy, fast and is carried out with manual winches.