25-08-2017, 09:32 PM
Generations of Network: 1G, 2G, 3G, 4G, 5G
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1. Introduction:
The cellular networks are evolving through several generations (figure1). The first generation (1G) wireless mobile communication network was analog system which was used for public voice service with the speed up to 2.4kbps. The second generation (2G) is based on digital technology and network infrastructure. As compared to the first generation, the second generation can support text messaging. Its success and the growth of demand for online information via the internet prompted the development of cellular wireless system with improved data connectivity, which ultimately lead to the third generation systems (3G).
3G systems refer to the developing technology standards for the next generation of mobile communications systems. One of the main goals of the standardization efforts of 3G is to create a universal infrastructure that is able to support existing and future services. This requires that the infrastructure be designed so that it can evolve as technology changes, without compromising the existing services on the existing networks. Separation of access technology, transport technology, service technology and user application from each other make this demanding requirement possible.
The 4th Generation (4G) wireless mobile internet networks are research items in academy, which will integrate current existing 3G cellular networks (i.e., OFDM, CDMA2000, WCDMA and TD_SCDMA) and Wi-Fi (i.e. Wireless LAN) networks with fixed internet to support wireless mobile internet as the same quality of service as fixed internet, which is an evolution not only to move beyond the limitations and problems of 3G, but also to enhance the quality of services, to increase the bandwidth and to reduce the cost of the resource.
The 5th wireless mobile multimedia internet networks can be completed wireless communication without limitation, which bring us perfect real world wireless – World Wide Wireless Web (WW). 5G is based on 4G technologies, which is to be revolution to 5G. During this processing, there are two kind of problems need to be solved. The first is wider coverage and the second is freedom of movement from one technology to another. The 6th generation (6G) wireless mobile communication networks shall integrate satellites to get global coverage. The global coverage systems have been developed by four courtiers. The global position system (GPS) is developed by USA. The COMPASS system is developed by China. The Galileo
System is developed by EU, and the GLONASS system is developed by Russia. These in depended systems are difficulty for space roaming. The task of 7th generation (7G) wireless mobile communication networks are going to unite the four systems to get space roaming. But we concentrate here only on 1G to 5G.
2. First Generation (1G) – Analog System:
1G refers to the first-generation of wireless telephone technology, mobile telecommunications. These are the analog telecommunications standards that were introduced in the 1980s and continued until being replaced by 2G digital telecommunications. The main difference between two succeeding mobile telephone systems, 1G and 2G, is that the radio signals that 1G networks use are analog, while 2G networks are digital.
Although both systems use digital signaling to connect the radio towers (which listen to the handsets) to the rest of the telephone system, the voice itself during a call is encoded to digital signals in 2G whereas 1G is only modulated to higher frequency, typically 150 MHz and up.
Mobile radio telephones were used for military communications in the early 20th century. Car-based telephones were first introduced in the mid-1940s. In fact, the first car-based telephone system was tested in Saint Louis in 1946. This system used a single large transmitter on top of a tall building. A single channel was used for sending and receiving. To talk, the user pushed a button that enabled transmission and disabled reception. Due to this, these became known as “push-to-talk” systems in the 1950s. Although these systems are quite old, taxis and police cars use this technology. To allow users to talk and listen at the same time, IMTS (Improved Mobile Telephone System) was introduced in the 1960s. It used two channels (one for sending, one for receiving – thus there was no need for push-to-talk). IMTS used 23 channels from 150 MHz to 450 MHz.
First-generation cellular networks were introduced in the 1980s. This started with the Advanced Mobile Phone Service (AMPS) that was invented at Bell Labs and first installed in 1982. AMPS has also been used in England (called TACS) and Japan (called MCS-L1). The key idea of 1G cellular networks is that the geographical area is divided into cells (typically 10-25km), each served by a “base station.” Cells are small so that frequency reuse can be exploited in nearby (but not adjacent) cells. This allows many more users to be supported in a given area. For example, as compared to IMTS, AMPS can support 5 to 10 times more users in the same 100-mile area by dividing the area into 20 smaller cells that reuse the same frequency ranges. In addition, smaller cells also require less powerful and cheaper, smaller devices to transmit and receive information.
Actually, the first generation wireless mobile communication system is not digital technology, but analog cellular telephone system which was used for voice service only during the early 1980s. This Advanced Mobile Phone System (AMPS) was a frequency modulated analog mobile radio system using Frequency Division Multiple Access (FDMA) with 30kHz channels occupying the 824MHz − 894MHz frequency band and a first commercial cellular system deployed until the early 1990’s.
The first commercially automated cellular network (the 1G generation) was launched in Japan by NTT (Nippon Telegraph and Telephone) in 1979, initially in the metropolitan area of Tokyo. Within five years, the NTT network had been expanded to cover the whole population of Japan and became the first nationwide 1G network.
In 1981, this was followed by the simultaneous launch of the Nordic Mobile Telephone (NMT) system in Denmark, Finland, Norway and Sweden. NMT was the first mobile phone network featuring international roaming. The first 1G network launched in the USA was Chicago based Ameritech in 1983 using the Motorola DynaTAC mobile phone. Several countries then followed in the early-to-mid 1980s including the UK, Mexico and Canada.
1G cellular networks are based primarily on analog communications. In North America, two 25 MHz bands are allocated to AMPS – one for transmission from base to mobile unit and one for transmission from mobile unit to base. Each phone has a 32-bit serial number and 10-digit phone number in its PROM (Programmable Read-only Memory). When a phone is turned on, it scans for control signals from base stations. It sends this information to the BS with strongest control signal and the BS passes this information to MTS (Master Switching Station) as a packet. The subscriber initiates a call by keying in a phone number and pressing the send key. The MTS verifies the number and authorizes the user. MTS issues a message to the user’s cell phone indicating send and receive traffic channels. MTS sends a ringing signal to the called party. Party answers; MTS establishes the circuit and initiates billing information. Either party hangs up; MTS releases the circuit, frees the channels, and completes billing.
2.1. Security Issues with 1G:
Analog cellular phones are insecure. Anyone with an all-band radio receiver can listen in to the conversation. Many scandals have been reported in this area. There are also thefts of airtime. Basically, a thief uses an all-band radio receiver that is connected to a computer. This computer can record the 32-bit serial numbers and phone numbers of subscribers when calling (recall that this information is sent as a packet). The thieves can collect a large database by driving around and can then go into business by reprogramming stolen phones and reselling them.
2.2. Paging Networks:
Paging networks are one of the oldest wireless technologies. They support one-way and two way alphanumeric messages between callers and pagers (beepers). The callers typically call a beeper company and leave a phone number and possibly a short message. Paging networks are being integrated with PDAs (personal digital assistants) like Palm Pilots. An example of paging networks is the BellSouth Clamshell Pager with keyboard.
2.3. Characteristics of Paging Networks:
Paging networks have been around for a while and were among the first wireless networks used for sending numeric and alphanumeric messages to external devices carried by mobile workers. These are specialized wireless networks for broadcasting a message to a specific pager to call back a specific number. Figure (2) shows a conceptual view of paging networks. The paging network provider (paging operator), such as Skytel, runs a paging control center which receives paging requests from regular phones, cellular phones, or other pagers and routes them to their destination pagers. The paging BTSs (Base Transceiver Stations) are connected to the paging control center through leased lines or wireless links such as satellites or wireless local loops.
The paging networks come in two flavors: one-way paging networks and two-way paging networks. The two-way paging networks allow pre-defined messages to be sent back by the receiver of the message. The commercial paging operators can establish a network that meets subscribers’ requirements and supports a wide range of paging devices. The paging devices can be equipped with sophisticated features such as priority paging, group paging, voice paging, voice prompts, and remote transmitter control.
A few characteristics of the paging networks are follows:
Common applications are personal numeric messaging for call-back, alphanumeric messaging (dispatching and service), and two-way messaging (call dispatching with confirmation).
Capacity and speed includes 1200 bps for older and 6400 bps for newer systems. The paging networks are slower but have different design criteria for delivering the message within specific time periods.
Frequency bands used include 800 MHz for older paging networks and 901-941 MHz, with gaps, for newer networks.
Components of a paging network are a personal paging device, a paging computer/server at the paging operator’s site, and a paging transmitter. These networks may also use satellites for national coverage.
Coverage is 95% of the US, thanks to many local, regional and national paging network providers.
Communications protocols supported include FLEX and ReFLEX developed by Motorola for two-way paging.
Security is low and has not been considered a high priority.
The advantages of paging networks are:
Very inexpensive
Easy to operate for sender (from any telephone) and receiver
Many options for users (numeric, alphanumeric, two-way, message storage)
Wide coverage at local, regional , national, and international levels
Good building penetration
The limitations of paging networks are follows:
Slow data transfer rate (1200 bps)
No acknowledgment (two-way paging costs extra)
Some of the available paging networks are overloaded, causing delays.
[attachment=29558]
1. Introduction:
The cellular networks are evolving through several generations (figure1). The first generation (1G) wireless mobile communication network was analog system which was used for public voice service with the speed up to 2.4kbps. The second generation (2G) is based on digital technology and network infrastructure. As compared to the first generation, the second generation can support text messaging. Its success and the growth of demand for online information via the internet prompted the development of cellular wireless system with improved data connectivity, which ultimately lead to the third generation systems (3G).
3G systems refer to the developing technology standards for the next generation of mobile communications systems. One of the main goals of the standardization efforts of 3G is to create a universal infrastructure that is able to support existing and future services. This requires that the infrastructure be designed so that it can evolve as technology changes, without compromising the existing services on the existing networks. Separation of access technology, transport technology, service technology and user application from each other make this demanding requirement possible.
The 4th Generation (4G) wireless mobile internet networks are research items in academy, which will integrate current existing 3G cellular networks (i.e., OFDM, CDMA2000, WCDMA and TD_SCDMA) and Wi-Fi (i.e. Wireless LAN) networks with fixed internet to support wireless mobile internet as the same quality of service as fixed internet, which is an evolution not only to move beyond the limitations and problems of 3G, but also to enhance the quality of services, to increase the bandwidth and to reduce the cost of the resource.
The 5th wireless mobile multimedia internet networks can be completed wireless communication without limitation, which bring us perfect real world wireless – World Wide Wireless Web (WW). 5G is based on 4G technologies, which is to be revolution to 5G. During this processing, there are two kind of problems need to be solved. The first is wider coverage and the second is freedom of movement from one technology to another. The 6th generation (6G) wireless mobile communication networks shall integrate satellites to get global coverage. The global coverage systems have been developed by four courtiers. The global position system (GPS) is developed by USA. The COMPASS system is developed by China. The Galileo
System is developed by EU, and the GLONASS system is developed by Russia. These in depended systems are difficulty for space roaming. The task of 7th generation (7G) wireless mobile communication networks are going to unite the four systems to get space roaming. But we concentrate here only on 1G to 5G.
2. First Generation (1G) – Analog System:
1G refers to the first-generation of wireless telephone technology, mobile telecommunications. These are the analog telecommunications standards that were introduced in the 1980s and continued until being replaced by 2G digital telecommunications. The main difference between two succeeding mobile telephone systems, 1G and 2G, is that the radio signals that 1G networks use are analog, while 2G networks are digital.
Although both systems use digital signaling to connect the radio towers (which listen to the handsets) to the rest of the telephone system, the voice itself during a call is encoded to digital signals in 2G whereas 1G is only modulated to higher frequency, typically 150 MHz and up.
Mobile radio telephones were used for military communications in the early 20th century. Car-based telephones were first introduced in the mid-1940s. In fact, the first car-based telephone system was tested in Saint Louis in 1946. This system used a single large transmitter on top of a tall building. A single channel was used for sending and receiving. To talk, the user pushed a button that enabled transmission and disabled reception. Due to this, these became known as “push-to-talk” systems in the 1950s. Although these systems are quite old, taxis and police cars use this technology. To allow users to talk and listen at the same time, IMTS (Improved Mobile Telephone System) was introduced in the 1960s. It used two channels (one for sending, one for receiving – thus there was no need for push-to-talk). IMTS used 23 channels from 150 MHz to 450 MHz.
First-generation cellular networks were introduced in the 1980s. This started with the Advanced Mobile Phone Service (AMPS) that was invented at Bell Labs and first installed in 1982. AMPS has also been used in England (called TACS) and Japan (called MCS-L1). The key idea of 1G cellular networks is that the geographical area is divided into cells (typically 10-25km), each served by a “base station.” Cells are small so that frequency reuse can be exploited in nearby (but not adjacent) cells. This allows many more users to be supported in a given area. For example, as compared to IMTS, AMPS can support 5 to 10 times more users in the same 100-mile area by dividing the area into 20 smaller cells that reuse the same frequency ranges. In addition, smaller cells also require less powerful and cheaper, smaller devices to transmit and receive information.
Actually, the first generation wireless mobile communication system is not digital technology, but analog cellular telephone system which was used for voice service only during the early 1980s. This Advanced Mobile Phone System (AMPS) was a frequency modulated analog mobile radio system using Frequency Division Multiple Access (FDMA) with 30kHz channels occupying the 824MHz − 894MHz frequency band and a first commercial cellular system deployed until the early 1990’s.
The first commercially automated cellular network (the 1G generation) was launched in Japan by NTT (Nippon Telegraph and Telephone) in 1979, initially in the metropolitan area of Tokyo. Within five years, the NTT network had been expanded to cover the whole population of Japan and became the first nationwide 1G network.
In 1981, this was followed by the simultaneous launch of the Nordic Mobile Telephone (NMT) system in Denmark, Finland, Norway and Sweden. NMT was the first mobile phone network featuring international roaming. The first 1G network launched in the USA was Chicago based Ameritech in 1983 using the Motorola DynaTAC mobile phone. Several countries then followed in the early-to-mid 1980s including the UK, Mexico and Canada.
1G cellular networks are based primarily on analog communications. In North America, two 25 MHz bands are allocated to AMPS – one for transmission from base to mobile unit and one for transmission from mobile unit to base. Each phone has a 32-bit serial number and 10-digit phone number in its PROM (Programmable Read-only Memory). When a phone is turned on, it scans for control signals from base stations. It sends this information to the BS with strongest control signal and the BS passes this information to MTS (Master Switching Station) as a packet. The subscriber initiates a call by keying in a phone number and pressing the send key. The MTS verifies the number and authorizes the user. MTS issues a message to the user’s cell phone indicating send and receive traffic channels. MTS sends a ringing signal to the called party. Party answers; MTS establishes the circuit and initiates billing information. Either party hangs up; MTS releases the circuit, frees the channels, and completes billing.
2.1. Security Issues with 1G:
Analog cellular phones are insecure. Anyone with an all-band radio receiver can listen in to the conversation. Many scandals have been reported in this area. There are also thefts of airtime. Basically, a thief uses an all-band radio receiver that is connected to a computer. This computer can record the 32-bit serial numbers and phone numbers of subscribers when calling (recall that this information is sent as a packet). The thieves can collect a large database by driving around and can then go into business by reprogramming stolen phones and reselling them.
2.2. Paging Networks:
Paging networks are one of the oldest wireless technologies. They support one-way and two way alphanumeric messages between callers and pagers (beepers). The callers typically call a beeper company and leave a phone number and possibly a short message. Paging networks are being integrated with PDAs (personal digital assistants) like Palm Pilots. An example of paging networks is the BellSouth Clamshell Pager with keyboard.
2.3. Characteristics of Paging Networks:
Paging networks have been around for a while and were among the first wireless networks used for sending numeric and alphanumeric messages to external devices carried by mobile workers. These are specialized wireless networks for broadcasting a message to a specific pager to call back a specific number. Figure (2) shows a conceptual view of paging networks. The paging network provider (paging operator), such as Skytel, runs a paging control center which receives paging requests from regular phones, cellular phones, or other pagers and routes them to their destination pagers. The paging BTSs (Base Transceiver Stations) are connected to the paging control center through leased lines or wireless links such as satellites or wireless local loops.
The paging networks come in two flavors: one-way paging networks and two-way paging networks. The two-way paging networks allow pre-defined messages to be sent back by the receiver of the message. The commercial paging operators can establish a network that meets subscribers’ requirements and supports a wide range of paging devices. The paging devices can be equipped with sophisticated features such as priority paging, group paging, voice paging, voice prompts, and remote transmitter control.
A few characteristics of the paging networks are follows:
Common applications are personal numeric messaging for call-back, alphanumeric messaging (dispatching and service), and two-way messaging (call dispatching with confirmation).
Capacity and speed includes 1200 bps for older and 6400 bps for newer systems. The paging networks are slower but have different design criteria for delivering the message within specific time periods.
Frequency bands used include 800 MHz for older paging networks and 901-941 MHz, with gaps, for newer networks.
Components of a paging network are a personal paging device, a paging computer/server at the paging operator’s site, and a paging transmitter. These networks may also use satellites for national coverage.
Coverage is 95% of the US, thanks to many local, regional and national paging network providers.
Communications protocols supported include FLEX and ReFLEX developed by Motorola for two-way paging.
Security is low and has not been considered a high priority.
The advantages of paging networks are:
Very inexpensive
Easy to operate for sender (from any telephone) and receiver
Many options for users (numeric, alphanumeric, two-way, message storage)
Wide coverage at local, regional , national, and international levels
Good building penetration
The limitations of paging networks are follows:
Slow data transfer rate (1200 bps)
No acknowledgment (two-way paging costs extra)
Some of the available paging networks are overloaded, causing delays.