1.0 Introduction
A mobile network is a wireless network that is distributed over several land regions known as cells. At least one transceiver called base station or cell site placed in the affixed location is used to serve every cell. A wireless connection in this case involves the use of unguided transmission mediums such as air, radio, satellite and others for transmission and reception of voice and messages. In mobile network connection, every cell uses dissimilar group of frequencies from the adjacent cells. It helps in avoiding interference and to ensure the provision of bandwidth inside every cell. This paper explains some of the mobile network technologies such as wireless local and wide area networks among others for successful connectivity. The paper ends with the conclusion drawn from the overall discussion (Gibson, 2012, Zhuang & Ismail, 2012).
2.0 Mobile network Technologies
2.1 Wireless Wide Area Network
Wireless Wide area network (WWAN) uses radio, satellite and mobile phone technology for data transfer between communicating devices. At present, a number of manufacturers do install a cellular radio within computing devices. This installation permits both sending and receiving of digital data along cellular radio frequencies in addition to transmission of voice communications coming from a similar device. The current rate of data transmission and reception ranges from 384 kilobits per second (Kbps) to 2.4 Megabits per second (Mbps). It is to say that wireless wide area network offers a wider range of connectivity support as compared to wireless local area network (Gibson, 2012).
2.2 Wireless Local Area Network and Blue tooth
Wireless local area network (WLAN) and Bluetooth can be defined as a radio based system used to convey information from one network device to a different one without the use of any guided transmission medium link. For instance, the infra red wave technology is used to transmit information signals via space in addition to offering wireless connectivity. The devices used in this technology especially those that conforms to 802.11 standard attain data transport speed of up to 108 Mbps. The wireless connectivity is extensively used in mobile computing to perform some work in multiple locations by professionals. Some examples include wireless LAN points of access which are accessible in public areas like cafes, airports and modern hotels. In this case, experts with notebook computers can easily connect to the internet from these locations. The links can be attained as simply as linking at home or from the office (Gibson, 2012, Sun, Fossa & Mak, 2011).
2.3 Voice and data cellular Network
A cellular (mobile) network provides several desirable features. Some of these features include extra capacity than one large transmitter given that a similar frequency can be employed for multiple connections provided they are in dissimilar cells. Another feature is where mobile devices use less power as compared to one transmitter or satellite because the cell towers are in proximity. In addition, there is larger coverage area than that of a single earthly transmitter. This larger coverage is due to extra cell towers which are no restricted by the horizon and which can be added indefinitely. Main telecommunications providers have deployed the voice and data cellular networks over the majority of occupied land areas. This deployment permits mobile phones as well as mobile computing devices to be linked to the public switched telephone network (PSTN) and even to the public internet. The private mobile networks can also be employed for research (Gibson, 2012).
In a system of cellular radio, the land region to be covered with radio service is segmented into regular cell shapes. The cells can be hexagonal, circular, square or other regular shapes. However, the hexagonal shapes are conventionally employed. Every cell is assigned with numerous frequencies that is f1 to f6 with a matching base stations. The set of frequencies can be reused in different cells as long as the similar frequencies are not reused in the adjacent neighboring cells since this may result to co-channel interference (Gibson, 2012).
2.4 Frequency reuse
Frequency reuse if a key feature of mobile/cellular network which makes it possible to increase coverage and capacity of mobile network. Reuse distance and reuse factor are the two elements that determine the frequency reuse. Frequency reuse is possible with cells separated by a large distance. The cells may vary in radius from 1 to 30 kilometers. Larger cells can further be sub divided into other cells. The cell boundaries can also overlap amid adjacent cells. The rate at which the same frequency can be used in the mobile network is the frequency reuse factor. The figures bellow shows frequency reuse in the conventional hexagonal shapes (Gibson, 2012).
- Commonly used cellular reused cells.
2.5 How to connect to a network
Wireless connections operate in the same way like the other wirelesss connectins in a network. The signals
3.0 Routing principles
3.1 TCT/IP protocol
The aim of internet protocol mobility is to uphold the transfer control protocol link amid mobile host while reducing the effects of site changes as the mobile host shifts around. It happens without having to alter the underlying transfer control protocol/Internet protocol. In order for the problem to be solved, the RFC permits for the type of the proxy agent to act as a middle man amid mobile host and the correspondent host (Soper et al., 2010).
3.2 Mobile addresses
The mobile terminal consists of two addresses namely permanent and home address and care-of address. The addresses are connected with the network that the mobile terminal is to visit. The home agent and the foreign agent are the two types of entities that comprise the implementation of mobile internet protocol. The home agent has the responsibility of storing the information concerning the mobile terminal whose permanent home address is the network of the home agent. The home agent thus acts as a router on a mobile host home network which on the other hand tunnels datagram for transmission to the mobile host at a time when it is away from home. It also maintains the location directory for the mobile host. The foreign agent stores information concerning mobile terminals that visit its network. The foreign agent also advertises acre- of addresses used by mobile internet protocol. In the case of absence of the foreign agent in the network of host, the mobile device has to take care of obtaining an address and advertising it by its way. The foreign agent also acts as a router on the visited network of the mobile host which offers routing services to the mobile host. The foreign agent de-tunnels and transmits datagram to the mobile host that was tunneled by the home agent of the mobile host (Soper et al., 2010).
3.3 Node to mobile communication
A node wanting to communicate with the mobile device within the mobile network utilizes permanent home address of the of the mobile device node. This mobile device becomes the destination address where data packets are routed to. Given that the home address sensibly belongs to the network connected with the home agent, the normal internet protocol (IP) routing methods relays these packets to the home agent. Instead of relaying these packets to the destination that is physically in the similar network like the home agent, the home agent redirects these packets to the remote address via an internet protocol tunnel. This packet redirection is done by encapsulating the datagram with the fresh internet protocol header by means of care of address of the mobile terminal. (Soper et al., 2010).
3.4 Mobile node as transmitter
The mobile node transmits packets directly to the other communicating terminal when acting as a transmitter. This transmission takes place without relaying packets via the home agent, by means of its permanent home address as the source address for the internet protocol packets. This kind of transmission is referred to as triangular routing (route optimization) mode. The foreign agent can use the reverse tunneling when required by tunneling the mobile packets of the terminal to the home agent. The home agent in turn relays them to the communicating terminal. It is required in networks where by gateway routers monitors that the source internet protocol address of the mobile host belongs to their subset. Reverse tunneling is the default behavior in Mobile IPv6 with route optimization being the optional behavior (Soper et al., 2010).
4.0 Network of Mobile phone
The mobile phone network uses the global system for mobile communication (GSM) network. Mobile phone is thus the most widespread example of cellular network. The mobile phone is used to make and receive calls via cell site or base station (BS). The radio waves help in the transfer of call and message signals to and from a given cell phone. Since radio frequencies are limited, the modem mobile phone network utilizes cells. The base stations and hand sets do change frequencies under the control of the computer. They also use transmitters of low power to permit the use of the limited number of radio frequencies simultaneously by several subscribers with low interference. The cellular network system is utilized by operators of mobile phones in order to attain both coverage and capacity for subscribers. If the geographical region is bigger, it is split into several cells to avoid signal loss along the line of sight. The splitting also allows the support of a large number of active phones in the region. Every base station is linked to telephone exchanges. (Switches). The switches are also linked to public telephone network (PTN) (Gibson, 2012, Zhuang & Ismail, 2012).
4.1 Mobile phone cellular Network structure
A simple analysis of cellular mobile-radio network comprises of a network of radio base stations having BS subsystem, the core circuit switched network for handling both calls, and texts. There is also packet switched network for handling of mobile data and the public switched telephone network to link subscribers to the global telephone network. This network is the base of GSM network system (Gibson, 2012).
4.2 The calling process
The mobile phone connects to the radio base station (RBS) at the point of the matching cell. The cell on the other hand links to the mobile switching center (MSC). The mobile switching center then offers a link to the public switched telephone network. The connection from the telephone to the radio base station is the uplink where as the other way is the down link. The radio channels efficiently employ transmission mediums via the use of frequency division multiplexing access(FDMA), Time division multiplexing access(TDMA), code division multiplexing access(CDMA) and space division multiple accesses(SDMA). The speed of connection increases from 1G, 2G, and 3G onwards. It for instance means that first generation (1G) mobile network devices are slower as compared to those of third generation (3G) (Gibson, 2012, Sun, Fossa & Mak, 2011).
4.3 hands over in Mobile phone network
As the phone subscriber shifts from one cell region to a different cell during the call process, the mobile station searches for a new channel to link to in order to avoid call drop. When a fresh channel is found, the network commands the mobile unit to change to the new channel. At the same time, the call is switched onto the fresh channel by the mobile unit (Gibson, 2012).
4.4 Trouble shooting for dial failure
There are various reasons why a mobile phone device may fail to receive or make a call in the dialing process. The reasons include improper dialing pattern used or tying to dial invalid number. Second is the issue of signal not strong enough for call completion. Third is that family mobile account may be inactive. Forth is that the device may need to be rebooted; that is, to be turned on and off again. Fifth is that extras pack is turned off. Next is that the low extras pack balance may be required. Finally is the minute restriction through family controls. To trouble shoot problems of making or receiving calls, you first of all ensure that you are in an area where there is a good signal. You can then check the family control settings in order to ensure that the call does not go to blocked numbers. If you are dialing an international number, check to ensure that there are enough funds in the user’s extra is pack for call completion. You should also check the extra’s pack to ensure it is not disabled. You can then make a call by using the full 11 digit phone number, which is, starting with 1, followed by area code and then the number respectively. Then you can reboot the phone. You can then try the call again a different number after reboot. If the call is successful, then the problem is with the phone number that was being dialed initially. Otherwise the issue remains with your service. You can also try to choose T- mobile’s network from your phone manually. Then you can test your SIM card in a different family mobile phone if possible to help find out if the problem is with your SIM card or your phone. If you are still unable to complete the call, the problem may be due to signal strength, battery strength number you are trying o dial, date and time of attempted call or dialing pattern, that is, 10 digit numbers versus 11 digit numbers. You can finally contact the customer care with the result of your trouble shooting. You can choose the option for handset or network support followed by network problem option when prompted at the main menu. In this case you can use a different phone other than your family mobile phone when calling customer service. The customer service team will be in a position to complete full trouble shooting on your family mobile phone (Church & Huang, 2011).
5.0 Conclusion
A mobile network is described by wireless communication nodes or devices working over dispersed geographical region. As nodes shift during their operation, the network partitions into a number of separate clusters. When the network has segmented, mobile nodes in dissimilar clusters cannot uphold connectivity because of inadequate radio communication range. The partitioned network will have a partial capacity in offering faultless communication services to sensors in addition to combat systems. To alleviate this difficulty, a subset of the mobile nodes can be collocated with and linked to an extra powerful communication node to form a gateway node. These extra powerful nodes have longer radio communication range and are assumed to be linked with one another form an upper tier such as satellite network. Therefore, connectivity is an important necessity for wireless sensor networks particularly in real time checking and data transport applications. Nevertheless, Mobile device movements and failures alter the topology of the first deployed network, which can enhance partitioning of the communication graph (Atay & Bayazit, 2010).
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