Tham khảo tài liệu 'nuclear power control, reliability and human factors part 4', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Design Considerations for the Implementation of a Mobile IP Telephony System in a Nuclear Power Plant 79 over Ethernet PoE mechanism according to the IEEE standard IEEE 2003 . In addition it is recommended that each wireless access point shall provide an independent 110 220 VAC voltage input. The legislation that the wireless access points must meet includes the regulation emitted by the Federal Communications Commission FCC Part FCC 2004 for digitally modulated intentional radiators devices and the security and electromagnetic interference requirements DoD 1999 IEC 2002 IEC 2005 in order to respect the acceptable electromagnetic interference and radiofrequency ranges for electronic communication equipment operating at frequencies above 1 GHz according to the Nuclear Regulatory Guide NRC 2003 emitted by the Nuclear Regulatory Commission. Wireless telephones The proposed wireless telephones will be used by personnel working in the external areas of the CNLV nuclear power plant conducting fieldwork so that they have to be robust designed for using in industrial and nuclear power plants in particular. Next the most relevant technical requirements the wireless telephones shall meet are presented. The wireless telephones shall be compliant to the IEEE IEEE 1999b ITU 2009 ITU 1988 ITU 2007 standards as well as to VoIP protocols emitted by international standards bodies. Besides they must support the capability of sending and receiving short text messages via open application interface. The wireless telephones shall support both static and dynamic DHCP IP addressing configuration and must operate in the ISM frequency band from to GHz according to the NOM-121-SCT-94 standard CCNNT 2001 issued by the Mexican Normalization in Telecommunications Consultative Committee. They shall be compliant to the IEEE Wi-Fi standard IEEE 1999b use direct sequence spread spectrum DSSS modulation technique and support .