Third generation (3G) mobile networks were first launched commercially in 2001 in Japan, allowing mobile broadband access up to several megabits per second. 3G standards include UMTS, HSPA, and EDGE, with later releases like HSPA+ able to provide peak speeds over 50 Mbps. 3G networks offered faster speeds and greater security than previous 2G networks, enabling new applications like mobile TV, GPS, and video calling.
The quality of optical fiber splicing is strongly dependent on environmental conditions during the splicing operation. To achieve high quality splicing, factors like dust, humidity, vibration, temperature, and having an appropriate working table must be considered. The document discusses stripping the fiber coating and alignment processes like PAS and LID that are important for splicing.
Third generation (3G) mobile networks were first launched commercially in 2001 in Japan, allowing mobile broadband access up to several megabits per second. 3G standards include UMTS, HSPA, and EDGE, with later releases like HSPA+ able to provide peak speeds over 50 Mbps. 3G networks offered faster speeds and greater security than previous 2G networks, enabling new applications like mobile TV, GPS, and video calling.
The quality of optical fiber splicing is strongly dependent on environmental conditions during the splicing operation. To achieve high quality splicing, factors like dust, humidity, vibration, temperature, and having an appropriate working table must be considered. The document discusses stripping the fiber coating and alignment processes like PAS and LID that are important for splicing.
The document provides a history of fiber-optic communications, beginning with early optical communication experiments in the 18th and 19th centuries. It then discusses key innovations in the 1950s and 1960s that led to the development of glass fiber with lower signal loss, paving the way for practical long-distance communication networks. The researchers Robert Maurer, Donald Keck, and Peter Schultz at Corning invented the first low-loss optical fiber in 1970, enabling vast increases in data transmission capacity compared to copper wire. Their breakthrough solved the problem of high signal loss identified as a barrier to long-range fiber networks.
This document lists 76 countries ranked by their percentage of 4G LTE mobile network coverage, with South Korea ranked first at 96% coverage followed by Japan at 93% and Norway at 87%. The United States and Hong Kong round out the top 5 with 87% and 86% 4G LTE coverage respectively.
OFDMA is a cellular air interface technology that uses orthogonal frequency division multiplexing to allow multiple users to access the network simultaneously over subsets of subcarriers. It provides superior air interfaces to CDMA and TDMA and is used in networks like WiMAX and LTE. OFDMA assigns subsets of subcarriers to individual users, whereas OFDM allocates users only in the time domain. OFDM uses a large number of subcarrier signals to carry parallel data streams.
Electromagnetic Wave propagation, ElectromagneticMuhammad Ibrahim
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This document discusses different methods of electromagnetic wave propagation through space. There are three basic paths: ground waves which follow the Earth's curvature for lower frequencies; space waves which travel line-of-sight; and sky waves which are reflected by ionized layers in the atmosphere, allowing higher frequency signals to travel farther than line-of-sight. The ionosphere, located 30-240 miles above the Earth, plays a key role in sky wave propagation by reflecting radio signals back to Earth, enabling long-distance HF radio communications.
Electromagnetic Wave propagation, ElectromagneticMuhammad Ibrahim
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Switch configuration (command)
1. Switch>en
Switch#config t
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)#vlan 2
Switch(config-vlan)#name MBBS
Switch(config-vlan)#exit
Switch(config)#int range fast
Switch(config)#int range fastEthernet 0/1 - fast
Switch(config)#int range fastEthernet 0/1 - fastEthernet 0/3
Switch(config-if-range)#swit
Switch(config-if-range)#switchport access vlan 2
Switch(config-if-range)#exit
Switch(config)#vlan 3
Switch(config-vlan)#name BDS
Switch(config-vlan)#exit
Switch(config)#int range fast
Switch(config)#int range fastEthernet 0/4 - fast
Switch(config)#int range fastEthernet 0/4 - fastEthernet 0/7
Switch(config-if-range)#swit
Switch(config-if-range)#switchport access vlan 3
Switch(config-if-range)#exit
Switch(config)#vlan 4
Switch(config-vlan)#name CIVIL
Switch(config-vlan)#exit
Switch(config)#int range fast
Switch(config)#int range fastEthernet 0/8 - fast
Switch(config)#int range fastEthernet 0/8 - fastEthernet 0/9
Switch(config-if-range)#swit
Switch(config-if-range)#switchport access vlan 4
Switch(config-if-range)#exit
Switch(config)#^Z
TRUNK ( communication between two switches )
Switch#en
Switch#config t
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)#int fas
Switch(config)#int fastEthernet 0/10
Switch(config-if)#swi
Switch(config-if)#switchport mode trunk