The Firefighters / First-Responder Locator and Monitoring System

 

There is a clear need to enhance the safety of our First Responders by continuously monitoring their position and sensing their vital signs and environment while in dangerous situations.  A wireless networking device attached to each person could do this, as well as serve as an alternate communication channel to his or her voice radio. The device would provide them with three major advantages:

 

• Location: Incident Commanders, back-up personnel and the Responders themselves will always know their precise position
• Monitoring of vital signs and environment: pulse rate, body temp, air temp, CO₂ gas, etc. are sensed and communicated to nearby monitoring stations
• Back-up two-way communications: panic button and other important information can be communicated as an alternate, robust path to the standard voice radio.

 But the challenges posed by the demanding environment in which these devices must work are great:

 

1. Traditional wireless does not operate well within buildings, under rubble, or inside tunnels.  Newer wireless technology such as Ultra Wide Band [UWB] shows promise, but commercial research here focuses on high data rate transfers, not on long range operation through structures.  Moreover, this technology is ideal for radar ranging, which can provide the needed position determination.
2. Another technique to extend network connections beyong radio range is Mesh Networking.  Devices that can't communicate back to a command center will connect with their nearest neighbor.
3. The complex algorithms to communicate, locate and sense the environment all must execute on a low power, portable microprocessor under extremely rugged circumstances.  Will all the necessary processing fit?  The results are needed in realtime, reliably enough so life critical decisions can be made.  Research must explore the practicality of executing all this software under realistic circumstances.

Several technology areas need to be advanced to make this concept a reality.  Spectracom is depending on the upstate NY academic community to further the state of the art in the following areas:

UWB – Ultra Wide Band Radio

Research the propagation of UWB signals in indoor, underground and other high multipath environments.

Syracuse University, Dr. Lisa Osadciw

Radio waves bounce off some objects and penetrate others.  Wireless operation inside buildings and other structures are exacerbated by this multipath effect.  Recent advances in semiconductors have opened up a wide frequency band, which shows promise in combating this problem.

Multi-Lateration Ranging and Position Determination

Research the optimum algorithm for combining multiple range measurements among several nodes of a mesh network along with other position cues to determine precise 3D locations for each node.

Syracuse University, Dr. Lisa Osadciw

Radar-like measurements of network traffic between nodes – measuring the time travel of the radio waves to determine distance – can provide 3-dimensional location fixes by geometrically combining many measurements.

Mesh Networking

Research the optimum Media Access Control and Networking layer algorithms for reliable, modest-speed data transfer which conserves battery power while simultaneously doing ranging.

Rochester Institute of Technology, Dr. Nirmala Shenoy

Responders will work in small groups or cohorts.  Their networking devices will follow a protocol so that several cohorts with many participants per group can simultaneously send data and measure range using the same radio spectrum without interfering with each other.

Embedded Sensor Systems and Software

Devise practical methods for integrating body and environmental sensors with the personal networking device for use under demanding situations.

State University of NY at Buffalo, Prof. Michael Buckley

Sensitive sensors on the individual need to be connected to the wireless networking device, possibly by additional very short range wireless links, and in transmitted in realtime to all participants on the network.

 

This is the research proposed for sponsorship by the CAT Development grant.  It is essential and complimentary to other related research on-going and funded by other agencies.  The diagram below illustrates all the technology areas needed for this complex system. 

 

Personal Wireless Electronics and Power Sources

Research innovative methods for powering the electronics and placing them and the antennas on the responder’s apparel.

National Science Foundation SBIR grant request (pending approval)

Kinetic energy converters for charging batteries; antennas woven into fabrics or molded into helmets; conductive textiles – these are some of the advanced technology that must be explored to create a usable networking device for life critical operations.

Feasibility Testing with Fire Fighters

Develop and demonstrate prototype sensors that will measure several parameters such as firefighter respiration rate, heart rate, local temperature, and volatile gases.

Rochester Institute of Technology’s Collaboratory, Dr. Robert Kremens, under NASA sponsorship.

We can enhance the safety of structural firefighters by monitoring their health, the immediate environment, and their location and communicating this information back to a command location outside the structure.

Geographic Information System Display

Integrate all the sensed information into a cohesive, visual situational awareness picture for Incident Commanders.  The presentation will be in three dimensions, with map and photo overlays and integrated into an informational database containing details on the responders and the environment.

Under investigation with commercial vendors for GIS software applications

Detailed Research Descriptions

SU

            Ultrawideband (UWB) signals have begun appearing in commercial products, primarily communications products. The most popular form of an UWB signal, (i.e., any signal with a bandwidth exceeding 20% of the center frequency or at least 500 MHz), is to take a traditional narrowband modulation like CDMA and spread it over the UWB bandwidth using orthogonal frequency division multiplexing. This is an easy first step into UWB signaling, which yields part of this new technology’s performance benefits. Once the signal is demultiplexed, the processing is identical to narrowband processing, and the analysis can be done without considering the wideband nature of the signal except for the increased number of signals multiplexed. However, this project will require the impulse form of the UWB signal in order to achieve a greater propagation robustness in the channel  due to the challenging environment and ability to locate people and objects in heavy multipath conditions. Thus, this project will significantly advance UWB signaling by designing a sensor network with the ability to transmit data and, simultaneously, locate people and objects in harsh environments.

            In communications, this problem is unique due to its need to communicate in the presence of heavy multipath with few errors and fewer users with no concern for transmission speed. Most commercial UWB communication products have the increased user capacity and the data transmission speed. Signal processing must focus on the time domain for UWB while traditional signal processing focuses on the frequency domain. A slight mismatch in frequency will not greatly impact an impulse UWB system performance. However, time synchronization and time measurement must be highly accurate for decoding the messages correctly. Spectracom is at an unique technology advantage through its ability to provide highly accurate time estimates, thus, being able to provide the critical accuracy required for this system.

            In location estimation, this system will be solve the problem again through accurate time measures and additional new location algorithms. Multilateration is a possible approach that iteratively arrives at the location estimate through successive attempts to match candidate locations with the measurements made by the sensors. There are a few factors that improve the location estimate from this approach. The most critical factor is, of course, the accuracy of measuring time. However, the sensors also need to surround the object or person to be located. In addition, variation in sensor height is required to achieve a sound height estimate. The accuracy of the people or object location relies directly on the accuracy of the sensor’s own location. Since GPS signals are difficult to maintain in buildings, caves, etc., a sensor location algorithm needs to be developed that combines GPS location updates and Kalman tracking, which will be applied to motion measurements made by the sensor.

            The ultrawideband signals in this system support two functions: communication and location estimation. Thus, the physical layer of the communication protocol must integrate the signal content and function. Sensors are transmitting signals that are making measurements and/or transmitting data and voice. Signal prioritization may be successful in accomplishing this but a new protocol approach such as ant agents may be necessary to “escort” the messages through the network. The “escort” is able to make rerouting decisions given the state of the channels as they dynamically change. The objective is to move through the degraded network performing the required functions while avoiding degraded nodes without greatly impacting system performance. Thus, a proposed cross-layer approach to mesh networking is needed, which incorporates a smart physical layer management algorithm. This project will create a cutting edge, cross-layer protocol that is tailored to sensor networks.

RIT

Under emergencies, it is necessary to set up an Ad Hoc Wireless Mesh network among the Responders, Command Base Station and other emergency handling units. Typically, in such areas the communications infrastructure has been disrupted. The mesh network has to be robust, reliable, have low latency in data transfer and easily deployable. The devices with the Responders will form an Ad Hoc Mesh Network. Responders will work in small groups and the devices will facilitate networking among several groups, where the participants can simultaneously send data and measure range without severe interference from one another.

 It is necessary to monitor the vital signs of the Responders. Sensors collecting the pulse rate, body temperature, air temperature and CO2 gas around a Responder will form a small personal area network, and the data so collected will be aggregated at the devices held by the Responders.

As the devices with the Responders are handheld, they have to conserve battery power. Traditional networking protocol stacks were developed for operational optimizations under normal conditions, hence are not suitable to the ad hoc networking requirements under emergency scenarios. A compact protocol stack, with functions from across several layers (of the normal OSI model or TCP/IP model) will have to be integrated in a cross-layered approach. Robustness, low latency and reliability are best achieved by through a low-collision medium access and a robust routing mechanism. I

IEEE 802.11 medium access is well known for its poor performance under an ad hoc network scenario. Besides collision control, traffic jamming has to be avoided at all costs in such emergency networks. Data prioritization is very essential, as vital communications across the responders should get priority over other data. Hence, it is not advisable for such emergency networks to operate using the 802.11 medium access protocol. A medium access with low collisions, high reliability and capability of data prioritizations is essential.

Route discovery and route establishment across several responders simultaneously is essential in emergency networks. These routes have to be robust i.e. on the failure of one route, other backup routes should take over to carry forth the data. These two major routing related challenges will be addressed in this project. Traditional reactive routing protocols for ad hoc networks like AODV and DSR or proactive routing protocols like OLSR lack in either the route robustness or the controlled flooding during route discovery or in both.

The primary data that is expected to be carried across in emergency networks are voice, short broadcast messages, sensor data and text messages. These will be carried   over the compact protocol stack outlined above. The proposed scheme will be physical layer agnostic.

Testing and Implementation:

    The proposed protocols will be tested using simulation approaches based on the well-known networking simulation tool Opnet. The protocols will be developed such that they can be easily programmed into FPGAs for initial prototype testing. For this purpose we need two dedicated PC that will run Opnet. The printer requested will be dedicated to this project.

UB

The University of Buffalo will use its Embedded Systems Computer, in conjunction with two graduate courses in Software Engineering and HW/SW Integration, and using faculty and two dedicated senior-level students, to build an embedded processor, body and physiology sensory system, and situation display for the NYSTAR project. The Embedded Systems Lab has experience in developing body-sensor telemetry systems for NASCAR, ingestible gastro-intestinal [GI] monitoring systems for Smartpill, Inc., and augmentative technology for the handicapped.

The embedded processor will be a ruggedized extended-temperature single board computer possibly in a PC/104 form factor (TBD), running Microsoft’s Embedded CE operating system, with software  developed under Mobile.NET. It will connect to physiology sensors and transmit data to the situation display.

The situation display will be a commercial laptop running Windows XP or VISTA, with software developed under Visual Studio.NET, which will display and log body sensor readings.

 

Glossary

 

Ad Hoc Wireless Networks – devices automatically recognize, connect and communicate with each other without any previous configuration commands.

AODV – Ad Hoc On Demand Distance Vectoring – a multi-hop networking technique for determining how to send data to a remote node across a mesh network.

DSP – Digital Signal Processing

DSR – Dynamic Source Routing - another multi-hop networking technique

First Responders – fire fighters, law enforcement, emergency medical services, and rescue workers, anyone that must respond to emergency situations and risk their lives for homeland defense.

FPGAs – Field Programmable Gate Arrays – electronic logic devices that can be programmed after they are in use.

IEEE 802.11 – the standard that defines the WiFi wireless networking protocol for our PCs.

Matlab – a well-known mathematical simulation and analysis tool.

Media Access Control – the manner in which multiple nodes on a network use the communication channel (the media).

Mesh Networking – a technique where wireless participants pass each other’s data across the network.  Most networks have a central hub that controls transmissions – our cell phones connect to the cell tower or our WiFi PCs connect to a wireless hub – but in a mesh network, peer-to-peer connections pass the data along to where it needs to go.

Multi-Lateration Ranging – radio waves travel at the speed of light.  By measuring the transit time of a data transmission, the range between a transmitter and receiver can be determined.  Measuring the range from several diverse nodes allows one to triangulate on their position in three dimensions.

Multipath – radio waves bounce off objects and walls, creating many signals at a receiver from just one transmitter.  Receivers have to sort out this jumble to choose the direct path signal.

OLSR – Optimized Link State Routing - another multi-hop networking technique

Opnet – a well-known networking simulation tool

OSI – Open Systems Interconnect – a universal standard for describing how computers communicate.

PC/104 – a standard format for embedded microprocessor circuit boards.

RF – Radio Frequency

TCP/IP – Transport Control Protocol/Internet Protocol – the primary manner which communications over the Internet occur.

UWB – Ultra Wide Band – a wireless technique for transmitting data over many frequencies to improve range and increase data speed.  The technique was first used by Marconi 100 years ago in creating the wireless telegraph but recent advances in digital signal processing technology is causing a resurgence in its use.