Mountains and Forests Remote Recovery

81 nology helps to saves lives. In Chapter 2 we have seen that a signal with a frequency exceeding several GHz can easily pass through materials compared to those signals with lower fre- quency. Low frequency signals are blocked or jammed by ob- stacles. This is best explained in the scenario of interruption of phone calls in a lift as the metal cage blocks the 900MHz cellu- lar signal. Thus, the firemen require a more efficient form of communication than a hand phone to lead them to safety and accomplishing their rescue mission. An essential and complete suite of a fire fighter is shown in Figure 3.6. This figure differs from Figure 3.4 as it comes with some changes in the equip- ment and with the transmission and reception of data capabili- ties. Communication devices that are provided have different functions in ensuring the fire fighter’s safety. The suit is fea- tured to protect both the fire fighter and the equipment itself from long term exposure to toxic gases and heat. Architecture of the communication devices must be designed to function within the suit at all time. Besides, suitable communication filtering should be fix to eliminate any surrounding noise that may affect communication. This is vital since communication should be established at all time during a rescue operation in a building on fire. Oxygen is very important in the scenario of a fire for a better chance of survival. Alert for the oxygen level need to be generated to allow the fire fighter have enough time to plan an escape or to have a supporting team bring in extra oxygen sup- ply before the oxygen finishes. This alert should be designed to notify the fire-fighters in a subtle manner so as not to cause anx- iety that could create a panic situation. It should ease the rescu- ing mission too. Beside the oxygen status, toxic and flammable gas detection equipment, video footage of rescuing task and on site scene is an option to be equipped too. This footage can aid the command center or offsite post to get a clearer picture of what happening in the building on fire. A reliable communica- tion network is essential to ensure the safety of the fire-fighters and the task goes on well. The conventional Very High Fre- quency VHF radio range between 30–300 MHz utilized by US 82 fire departments have been reported to possess several ineffi- ciencies based on the TriData Corporation 2005 report. 800 MHz signal band for safe public radio communication has been implemented by the Federal Communications Commission FCC so that it does not interrupt the commercial broadcast signal and to reduce the spectrum from overcrowding and to prevent interference. However, the fire department uses differ- ent radio channels and interoperability becomes the main prob- lem. Therefore, the question arises whether to standardize the communication system used by the fire department. At a glance, satellite communication may fit the best since it has good coverage and perforation criteria. Satellite phone is a good solution for conventional communication with the offsite sup- porting team and the accuracy of determining the location prior to rescue is less demanding. Positional precision of global posi- tioning system GPS that is aided by satellite varies on many factors such as position of the satellite and the dilute of preci- sion DOP that is caused by nearby buildings. GPS is accurate up to a radius of several meters. So while carrying out a rescu- ing mission, a precise location is important than the range of location provided by GPS. GPS can generate a wrong analysis and mislead the rescue team to go to the wrong floor of the building and waste precious time. Thus satellite communication is an improper remedy for fire rescue. Another solution is radio frequency identification RFID for short range path recognition and marking which creates auto- matic visible marking along the route used during the mission. The technology used need to be fulfil certain criteria such as being lightweight and user friendly, accurate tracking of loca- tion, able to penetrate through an array of materials liberally used in the construction of buildings and has the ability to with- stand heat. Till today no single device has the technology to fa- cilitate all the aforementioned criteria. Incorporating different