EE 300W: The Design Process
Self-Reliant
Temporary Mobile
Cellular Station for
Rapid Infrastructure
Replacement
A Dell Social Innovation Challenge Project
Team RamRod
23 January 2013
1. Abstract
A portable cellular tower can be used as a hub for emergency 9-1-1 communication.
Existing mobile and monolithic cellular towers are powered by either a local power grid
or a diesel system. These towers a susceptible to a loss of electricity during a power grid
failure.
A system independent of the electrical grid, powered by wind and/or solar energy, can be
used as a vital communication tool during natural or man-made disasters. This system
temporarily replaces the existing cellular network when the local power grid is not
operating.
2. Introduction
During an extended loss of communication infrastructure, it is vital to provide a reliable
emergency communication system. Populations require the means to call for emergency
assistance. Modern mobile cellular towers are in threat of loss of electricity during a
power grid failure from natural or man-made disaster (i.e. forest fires, hurricanes,
flooding, blackouts, etc.). A mobile cellular station with independent power sources and a
satellite uplink is a reliable communication hub for emergency calls. Wind and solar
power, supported by a backup diesel generator with a deep cycle battery, can meet the
operating requirements for a mobile cellular station.
An alternative solution would be a conservative mobile cellular tower that is capable of
harnessing electrical power into a battery pack via wind and solar sources from the
natural environment. This energy can then be used to meet the requirements necessary to
transmit and receive communication signals to an existing satellite network. This
alternative completely removes the requirement of being connected to a local power grid,
such as in the modern mobile cellular tower. It also greatly reduces the need to rely on
diesel fuel as the main mobile cellular tower power energy.
3. Rationale
With no reliable infrastructure during a natural disaster, the only means of long distance
emergency communication for the general population is a mobile cellular network. The
network must be able to supply its own power and transfer communication signals out of
the area affected by a loss of infrastructure. By using multiple power generator methods
and storage in the event of a temporary energy deficit, a reliable cellular network can be
established. By using a mobile platform, such as a vehicle trailer, the solution can be
rapidly deployed to the emergency area. Using a satellite uplink will extend the
communication range to areas unaffected by the loss of infrastructure and provide a
reliable connection.
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4. Implementation
The minimum effective range shall be 5km with typical cellular tower spacing of 2km.
(“Frequently Asked PCS Questions” 2013). This range requires a power supply capable
of providing 3kW of power (“Power system considerations for cell tower applications”,
2011). The satellite transceiver will connect to an existing satellite network. In normal
operation, the wind and solar generators will provide all necessary power, with the excess
power stored in a deep-cycle battery system capable of power the system for 12 hours. A
diesel generator will provide support power if the battery capacity is depleted to the
battery’s minimum safe voltage level. The system shall weigh no more than 8000lbs.
This will allow the system to be transported by a Sikorsky UH-60 Black Hawk
helicopter.
To facilitate communication on all major US cellular networks, the system will transmit
and receive on the following standards and frequencies:
A. CDMA: 800/850/1700/2100 MHz
B. GSM: 850/1700/2100 MHz
The system will function as seen in Appendix A. System Block Diagram.
5. Value Statement
The need for communication between the general public and emergency services is less
reliable and in higher demand in times of man-made and natural disasters. Current
portable cellular towers are designed to supplement permanent towers. These portable
cellular towers also rely on infrastructure that is made unreliable by disasters.
By combining current portable cellular technology with renewable energy, a system that
is independent of the power grid and other local infrastructure can be created. This
system can provide the public with the means to call for emergency responders when all
permanent systems have failed. For victims of the Northeast Blackout of 2003, 2005’s
Hurricane Katrina, and 2012’s Hurricane Sandy this system could have proved invaluable
to the public and emergency responders and may have even saved lives.
6. Conclusion
These portable cellular towers can be setup to provide large coverage areas for disaster
regions. With each unit providing its own energy, the entire network can run infinitely for
indefinite periods of time. These networks will provide the public with the means to call
for help, and provide emergency services to send reverse 9-1-1 calls and text messages to
aid in recovery and public safety.
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7. Appendices
A. System Block Diagram
B. References
i.
“Power system considerations for cell tower applications”, by Wissam
Balshe, Cummins Power Generation, 2011.
ii. “Frequently Asked PCS Questions”,
www.arcx.com/sites/faq.htm#SiteRange, Accessed January 23, 2013.
Mikes Overall Comments (to be deleted before submission)
I think we followed the criteria for each section as described in the handout.
I like the way it reads and flows smoothly. I think we removed all of the
choppy/”worded” sentences and replaced them with more meaningful ones.
The only changes I would make are the comments: WMC1) I feel like we
should bluntly state our advantage over the present technology. I think it not
only ensures the audience understands but also creates concrete evidence as
to why our design is better. WMC2) I remember professor saying that
sometime chronological order is bad but rather but things that catch your eye
and are most important. Should keep these events in the order they are (most
impactful to least impactful) or rearrange from (2003-2005-2012)??
Other than that im cool with the paper and ready to submit tomorrow AM.
George’s comments:
(WMC2) I rearranged the dates to 2003-2005-2012 because he said people
read the first and last parts of things and it sounds better.
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