[1] TCP/IP Protocol Suite Fourth Edition Behrouz A. Forouzan
[2] http://en.wikipedia.org/wiki/International_Organization_for_Standardization
[3] http://en.wikipedia.org/wiki/ITU-T
[4] http://www.techstreet.com/info/etsi.tmpl
[5] http://evolving-technology.blogspot.com/2009/04/global-system-for-mobile-communication.html
[6] http://en.wikipedia.org/wiki/Reference_architecture
[7] Mehrotra, Asha. GSM System Engineering. Norwood, MA: Artech House, Inc., 1997.
[8] http://www.cs.ucl.ac.uk/staff/t.pagtzis/wireless/gsm/arch.html
[9] http://www.telecomspace.com/3g-umts.html
[10] http://www.networkdictionary.com/wireless/umts.php
[11]www.umtsworld.com
[12] www.umtslink.at
[13] http://www.freesoft.org/CIE/Topics/15.htm
[14] http://encyclopedia2.thefreedictionary.com/ISO%2FOSI+Reference+Model
[15] http://en.wikipedia.org/wiki/OSI_model
[16]http://www.technologyuk.net/telecommunications/communication_technologies/asynchronous_transfer_mode.shtml
[17] http://it.toolbox.com/wiki/index.php/IEEE_802
[18] http://www.eeherald.com/section/design-guide/ieee802_3.html
[19] http://www.profroark.com/UnixFiles/TCPIP_OSI_Model.pdf
[20] http://docwiki.cisco.com/wiki/X.25
[21] http://www.sarahgaskins.com/blog/
[22] http://en.wikipedia.org/wiki/Internet_Protocol
[23] http://fab.cba.mit.edu/classes/MIT/961.04/people/neil/ip.pdf
[24] http://en.wikipedia.org/wiki/Transmission_Control_Protocol
[25] http://en.wikipedia.org/wiki/Network_interface_controller
[26] http://en.wikipedia.org/wiki/Ethernet_hub
[27] http://en.wikipedia.org/wiki/Network_switch
[28] http://www.javvin.com/etraffic/network-router.html
[29] http://en.wikipedia.org/wiki/Bridging_(networking)
[30] http://forums.hostsearch.com/showthread.php?5432-Difference-Between-IDS-Firewall-amp-Antivirus
[31] http://en.wikipedia.org/wiki/Intrusion_detection_system
[32] http://en.wikipedia.org/wiki/Firewall_(computing)