This paper presents a low cost wireless sensor network system which is developed to be an alerting system for relatives or caregivers when the elder is immobile for a long period. The alerting signal is sent via the Internet link and a mobile phone. Remote transducers capture input signal from the mobility subject. If the target subject has immobilized behavior for long period which is analyzed abnormal condition the system will send the alerting messages to a selected mobile phone or Internet link. After detection of motionless elder from the set–point periods the system immediately distributes messages via SMS on the mobile network and a server to warn a relative or a caregiver with the image option to send. The sensor modules have ease-ofinstallation with coverage area nearly 3 square meters 80 % of detection level suitable for a small room and a bathroom