Communications Modes Table Mode of Communication How it Reliability Availability Advantages Limitations Runners Volunteers carry Extremely reliable Any reliable person Reliability Distance and time messages from can be used as a Flexibility Requires written one location to runner information for another Familiar with accuracy environment Availability Availability Requires familiarity No special training with the area Landline Telephones Phones that are Very common Familiarity Not mobile May operate during powered by power failures, but Commonplace System overloads themselves and handheld batteries can easily rely on local die and digital phones Enhanced 9-1-1 telephone lines may or may not work Network Data transfer susceptible to Local telephone system physical damage generally fails when a May be affected by large number of people failure in an area attempt to use phone at the same time Cellular Phones Phones that Very common Vulnerable to the same Familiarity Towers may fail transmit signals weaknesses as due to power Mobility relayed by cell outage or damage telephones phone towers Commonplace System overloads Cell towers require easily electricity to operate Text messaging Local service (voice) Requires less Requires bandwidth may get knowledge of generally fails when a – through when will numbers large number of people not in an area attempt to May be dependent use service at the same Camera phones on landlines time
Communications Modes Table Mode of Communication How it Reliability Availability Advantages Limitations Runners Volunteers carry messages from one location to another Extremely reliable Any reliable person can be used as a runner Reliability Flexibility Familiar with environment Availability No special training Distance and time Requires written information for accuracy Availability Requires familiarity with the area Landline Telephones Phones that are powered by themselves and rely on local telephone lines May operate during power failures, but handheld batteries can die and digital phones may or may not work Local telephone system generally fails when a large number of people in an area attempt to use phone at the same time Very common Familiarity Commonplace Enhanced 9-1-1 Data transfer Not mobile System overloads easily Network susceptible to physical damage May be affected by failure Cellular Phones Phones that transmit signals relayed by cell phone towers Vulnerable to the same weaknesses as telephones Cell towers require electricity to operate Very common Familiarity Mobility Commonplace Text messaging Towers may fail due to power outage or damage System overloads easily Local service (voice) generally fails when a large number of people in an area attempt to use service at the same time Requires less bandwidth – may get through when will not Camera phones Requires knowledge of numbers May be dependent on landlines
CERT-Emergency-Communications-Module.docx