LifeNet Emergency Communications Network - Voice over ad hoc Wi-Fi

evought's picture

The LCSA is exploring local deployment of the prototype LifeNet software stack as "a WiFi-based data communication solution designed for post-disaster scenarios". LifeNet is a fault-tolerant multipath routing framework which uses COTS (Commodity Off-The-Shelf) 802.11.x WiFi equipment to route emergency traffic from device to device until it can reach functioning infrastructure. This emergency traffic can include cell-phone voice and text communications on WiFi-capable smartphones and can make use of existing in-home wireless routers and laptops as links in the emergency communications chain. A Huffington Post article, "LifeNet Enables Wireless Communications When Internet Goes Down" describes how such a system might be used. This article lays out some of the considerations specific to Lawrence County and the LCSA and describes our current progress.

Missouri bases its emergency communications network around the 6m Amateur Radio band (regional coverage) and the SkyWarn system uses the 2m Amateur Radio band (local area coverage, 10-15 miles). Several amateur-operated 2 meter repeaters with backup power extend the range of 2 meter mobile and handset radios in Lawrence County's more populated areas. ARES/RACES volunteers operating these radios connect major emergency services together in the event of a disaster, able to transmit voice, code, and low-bandwidth data (via AX.25 packet radio links). Within the auxiliary, a number of LCSA volunteers with Amateur Radio Licenses and ARES training will provide both communications for emergency call-up and coarse-grained field communications without having to draw down ARES resources. Short-range COTS 2-way radios will then be used locally (<3 miles or over a square with 3 sections to a side) to connect us to our field dispatch and then to the existing emergency communications network.

There is, however, no system in place to provide for citizen communications to emergency services or for two-way communications with, say, local Neighborhood Watch segments. Therefore, it is conceivable that, e.g. a house could burn down during a phone-system outage or a resident could have a heart-attack and there would be no way to call for help. Both HAM and GMRS radios do have a limited ability to patch POTS (Plain-Old Telephone System) calls, routing a radio call from an area without phone service to an area with radio service and from there to 9-1-1 dispatch. REACT, a volunteer organization to monitor citizen radio frequencies for emergency calls and then perform that dispatching has never been implemented in Missouri, neither law enforcement nor EMS (for the most part) listen for those calls and fewer people today have usable 2-way radios to call for help in the first place. In the long run, work to increase the level of 2-way radio use and community training, including ARES/RACES operators at the Neighborhood Watch level (depending on runners or horse couriers within localities if necessary) is highly desirable, but another solution for Lawrence County is desirable which can make use of equipment and skills already present and widely dispersed and which will supplement the ARES/RACES/REACT capabilities. This is where LifeNet comes in, providing a method to route cell-phone calls and text messages using existing WiFi-capable handsets and existing routers.

LifeNet comes as a software protocol stack which can be installed on Android smartphone handsets, certain commodity Linux-based WiFi routers (e.g. the LinkSys WRT series routers), and laptops running the Linux operating system (Laptops not running Linux can potentially be converted to LifeNet-capable routers with the use of a bootable CD-ROM image and then returned to normal service after the emergency). Both Linux and LifeNet are freely available systems and the software could be (must be) pre-positioned to be available for emergency use with additional software copies and instructions at central locations. Restaurants, cafes, and hotels which already offer WiFi service to customers would be prime targets for emergency service. Monett is home to a wireless broadband service (Mo-Net) which covers a considerable area around the city and into neighboring farm communities.

Lawrence County has a relatively low population density. This is an advantage in that the amount of traffic needing to be routed is comparably very small but a disadvantage in that there are large zones which would not be covered by cafe WiFi routers. This problem has been one of our primary areas of investigation and experimentation and has yielded some interesting results. Hi-gain/long-range WiFi equipment is readily available which can cover from 1 to 10 miles depending on terrain and circumstances (our record so far is a 12-mile connection; 3 miles is more realistic) as long as the number of users and amount of traffic remains low. This is accomplished with USB-based wireless adapters and an external antenna or by attaching an external hi-gain antenna on WiFi routers which have that capability. Such equipment is in the sub-$200 range with usable laptop wireless adapters (with antenna) in the $50 range. Some of the external antenna options even have magnetic mounts or suction cups for attachment to vehicle roofs or windows. It would be quite possible to place such inexpensive wireless routers (and a small backup power system) at strategically-located farms in the area. They would provide normal WiFi access outside emergencies and switch over into backup communications systems during an outage.

An additional advantage to such an emergency wireless system is that it can be used as a local-area backhaul for high bandwidth data communication for emergency services. 802.11g WiFi routers provide 54 Mb of bandwidth which would be more than adequate for neighborhood watches, for instance, to transmit a picture of a suspect vehicle or of a missing child, to send documents, or to access the disaster response manuals people forgot to download before the emergency. Android smartphones can also function as additional Push-To-Talk handsets for local volunteers. Email can be routed locally through WiFi until it can reach the HAM packet radio network (or satellite internet connection) and the wider world. WiFi also provides a straight-forward way to apply industry-standard and off-the-shelf encryption to some of these emergency communications (consider HIPAA requirements and transmission of medical records, for instance). Perhaps more important than encryption, it can be combined with digital signing to verify and validate critical emergency communications.

The current status of this effort in Lawrence County is that we are experimenting with a small amount of hardware, including Panasonic Toughbook ruggedized laptops and LinkSys routers with external antennae for field use and with the software for Android smartphones for more general deployment. The hardware is solid and we have been very pleased with its performance. The software is much more shaky, being in the active development stage and some of the builds we have gotten from the developer do not even compile/install. Rapid progress is being made, however, and the process of setting up the system is becoming easier. I expect major developments to occur within the next six months with perhaps initial deployment beginning in the late 2012 or early 2013 timeframe.


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