Professional Pilot, October 2016

can dial 3001 12345 to open up a plethora of information One of the categories is average RSRP Reference signal received power a metric indicative of strength specific to LTE Numbers in the order of 50dBm are considered excellent whereas those towards 120 are on the verge of leaving the coverage area a smaller negative number is preferred LTE capable phones operating on a CDMA network do have SIM cards one of the exceptions to the CDMA rule What routers do and why they are important Aside from savvy computer enthusiasts most people have no idea what a router is or how it works despite the fact they use it every day To get a true sense of purpose its necessary to talk about getting online when personal computers first became available Computers were expensive so a single unit or none at all was the norm for the majority of households Interacting with the outside world consisted of taking a landline phone and attaching it to a component that converted the analog signal from the phone line into a digital computer format and vice versa called a modulator demodulator or modem Those who used an early generation device will recall the annoying cacophony of screeches and tones it made while connecting The modem is the conduit between the computer and the Internet service provider ISP It makes the connection possible 94 PROFESSIONAL PILOT October 2016 Rockwell Collins eRouter allows pilots to access ARINCDirect services like flightplanning and weather in addition to enabling network connectivity and managing media for passengers Modems can still use traditional phone lines although fiber optic and coaxial cable are more advanced and faster mediums of transmission A single computer only needs a modem to get online although you wouldnt want to do so more on that below But what happens when several computers or electronic devices want to access the Internet simultaneously Thats where the router comes in It combines all the devices into and network and directs traffic accordingly Sometimes the router directs traffic to and from the Internet and at other times it sends signals back at forth between components on the network for example to a printer With a traditional router connections are hard wired via Ethernet or USB cables A wireless router does the exact same thing sans the cables Home TV phone Internet providers usually combine a modem and router into a single multipurpose box inadvertently adding to the confusion of what it actually does Using a router even when not required adds an extra layer of security because of the way it handles subsystems within its purview Every device on the Internet is assigned a unique string of numbers know as an Internet Protocol IP address The router gives each component on the network a local address but only broadcasts a single IP address to the outside world The number of components on the network more specifically the IP address of each one are not revealed effectively shielding devices from targeted hacking Understanding Wi Fi technology and routers The irony about the current proliferation of Wi Fi devices is that the concept achieved prominence on radio bands initially dismissed as junk and considered somewhat useless In 1985 the Federal Communications Commission FCC allowed 900MHz 24GHz and 58GHz to be used without a license as long as operators did not interfere with the limited number of devices currently using those frequencies like microwave ovens Another caveat was that the bands could be used for communication purposes if the methodology dispersed the signal over multiple frequencies rather than 1 in particular called spread spectrum In the late 80s the concept found practical application in the form of wireless cash registers Unfortunately because no standard existed products and parts were not compatible or interchangeable creating havoc for the industry In an attempt to find answers several parties submitted the problem to the Institute of Electrical and Electronics Engineers IEEE a standards organization made up of experts in the field The inquiry fell within the area of expertise of an IEEE subcommittee designated as 802 Communication standards published under the guidance of the 802 group are identified with 802 followed by a period and additional numerals The number 11 specifies the rules apply to over the air modulation or more commonly wireless When the des