Showing posts with label gsm. Show all posts
Showing posts with label gsm. Show all posts

Thursday, September 09, 2021

Mobile phone and Network

All mobile operations rely on power. If we want to do more operations, energy conservation is the most important issue in wireless mobile computing due to the power limitation of mobile units. We often argue with friends about energy consumption. Power consumption is an important issue in mobile ad hoc networks.

Today, human life is completely dependent on mobile devices. Therefore, power consumption is very important in ad hoc mobile networks.

 

Mobile:

Mobile is a device that can be moved from one place to another. Mobile devices are wireless devices and they are very useful for many tasks.

Mobile phone (also known as a cell phone, cell phone, hand phone, or telephone for short) is a phone that can make and receive calls over a radio link while moving over a wide geographic area. To do this, it connects to the cellular network provided by the mobile device, which allows access to the public telephone network. In contrast, cordless phones are only used within a short distance of a single dedicated base station.

In addition to phones, modern mobile phones also support a variety of other services, such as SMS, MMS, email, Internet access, short-range wireless communication (infrared, Bluetooth), business applications, games, and photography. Mobile phones that provide these and other more general computing capabilities are called smart phones.

The first portable mobile phone was demonstrated in 1973 by Motorola's John F. Mitchell and Dr. Martin Cooper using a mobile phone weighing approximately 4.4 pounds (2 kg). In 1983, DynaTAC 8000x took the lead in the market. From 1983 to 2014, global mobile phone users increased from zero to more than 7 billion, penetrated 100% of the world's population, and reached the bottom of the economic pyramid. In 2014, the main mobile phone manufacturers were Samsung, Nokia, Apple and LG.

 

History:

Handheld cordless mobile phones are an ancient dream in radio engineering. One of the earliest descriptions can be found in Robert Heinlein's 1948 science fiction novel "Space Cadet." The protagonist has just left for Colorado from his home in Iowa, and the phone in his pocket receives a call from his father. Before heading to Earth orbit, he decided to send the phone home, "because it is so short that it can only reach the relay office on earth." Ten years later, Arthur C. Clark (Arthur C. Clarke) An Clarke's article envisions a "personal, small and compact transceiver, and everyone can carry one." Clark wrote: "We can call anyone anywhere on the planet by dialing a number." In Clark's vision, such devices will also include means of global positioning so that "no one gets lost again." Later, in the "Overview of the Future," he predicted that this device would appear in the mid-1980s. The early predecessors to the cell phone included analog radio communications from ships and trains. The race to manufacture true portable telephone equipment began after World War II and many countries are developing it. The progress of mobile phones can be traced back to early "0G" (generation zero) services, such as the Bell System mobile phone service and the enhanced mobile phone service of its successors. These "0G" systems are not cellular systems, they support few simultaneous calls and are very expensive.

Motorola demonstrated its first handheld mobile phone in 1973. NTT launched the first commercial automated cellular network in Japan in 1979. In 1981, the Nordic Mobile Telephone (NMT) system was subsequently launched simultaneously in Denmark, Finland, Norway, and Sweden. Several other countries followed suit in the early and mid-1980s. These first generation ("1G") systems can support more simultaneous calls, but still use analog technology.

In 1991, Radiolinja launched second generation (2G) digital cellular technology based on the GSM standard in Finland, sparking competition in the industry as new operators challenged existing 1G network operators.

Ten years later, in 2001, NTT Do Como launched the third generation (3G) of the WCDMA standard in Japan. It is closely followed by the 3.5G, 3G + or Turbo 3G enhancements based on the High Speed ​​Packet Access (HSPA) series, which allow the UMTS network to have higher speed and data transmission capacity. From 2001 to 2009, it is clear that at some point, 3G networks will be overwhelmed by the growth of bandwidth intensive applications such as streaming media. Therefore, the industry has started looking for data-optimized fourth-generation technology, which is expected to increase the speed to 10 times that of existing 3G technology. The first two commercial technologies known as 4G are the WiMAX standard (provided by Sprint in the US) and the LTE standard, initially provided by TeliaSonera in Scandinavia. 

 

Features of Mobile Phones:

All mobile phones have many common features, but manufacturers are also trying to implement additional features to differentiate their products and make them more attractive to consumers. This has led to great innovations in mobile phone development over the past 20 years. Common components on all phones are:

• Battery, which provides power for phone functions.

• An input mechanism that allows users to interact with the phone. The most common input mechanism is the keyboard, but touchscreens can also be found on most smartphones.

• In response to user input on the screen, display text messages, contacts, and more.

• A basic mobile phone service that allows users to make calls and send text messages.

• All GSM mobile phones use SIM cards to allow the exchange of accounts between devices. Some CDMA devices also have similar cards called UIM.

• Individual GSM, WCDMA, iDEN devices and certain satellite phones are uniquely identified by International Mobile Equipment Identity (IMEI) numbers.

Low-end phones are usually called feature phones and provide basic phone functions. Mobile phones that have more advanced computing capabilities through the use of native software applications are called smart phones.

However, in terms of sound quality, smartphones and feature phones are very limited. Some functions that can improve audio quality, such as LTE voice and high-definition voice, have appeared, and are usually available on newer smartphones. Sound quality is still a problem for both of you, because it depends not so much on the phone itself as on the quality of the network, in case a long time passes and a bottleneck/blocking point is found on the way. Therefore, in long distance calls, even LTE voice, high definition voice and other functions may not improve the situation. In some cases, smartphones can even improve the audio quality of long distance calls by using VoIP phone services and other people's WiFi / Internet connections. Launched several series of phones to address specific market segments, such as RIM BlackBerry that focuses on the email needs of corporate / corporate customers; Sony Ericsson `Walkman` series mobile phones / music and` Cyber ​​shot` series mobile phones / cameras; Nokia N series, Palm Pre, HTC Dream and Apple iPhone multimedia phones.

 

Using Mobile Phones:

Mobile phones have many uses, such as keeping in touch with family members, conducting business, and using the phone in emergency situations. Some people carry more than one mobile phone for different purposes, such as business and personal use. You can also use multiple SIM cards to take advantage of the different calling plans; specific plans may offer cheaper local calls, long distance calls, international calls, or roaming. Mobile phones are also used in various social settings, such as:

• A Motorola study found that one in ten mobile phone users owns a second phone, and that phone is generally kept secret from other family members. These phones can be used for activities such as extramarital affairs or secret business transactions.

• Some organizations assist victims of domestic violence by providing mobile phones for use in emergency situations. These are usually refurbished phones.

• The appearance of text messages gave rise to mobile novels. The first literary genre to appear in the honeycomb age, the first to be sent by SMS to a website that collects complete novels.

• Mobile phones also promote activism and public journalism that Reuters and Yahoo are exploring. And small independent news companies, like Sri Lanka's Jasmine News.

• The United Nations reports that mobile phones are spreading faster than any other technology and can improve the lives of the poorest people in developing countries by providing access to information where there are no landlines or the Internet, especially in least developed countries. Country: The use of mobile phones has also led to a large number of micro-enterprises by providing jobs, such as selling airtime on the street and repairing or refurbishing mobile phones.

• In Mali and other African countries, people used to travel from village to village to inform their family and friends about weddings, births and other events. These activities are now avoided within mobile phone coverage, which is usually better than landline coverage. The coverage is greater.

• The television industry has recently started using mobile phones to promote live television viewing through mobile applications, advertising, social television, and mobile television. 86% of Americans use cell phones while watching television.

• Mobile phone sharing is common in some parts of the world. It is common in Indian cities because groups of family and friends often share one or more mobile phones among their members. There are obvious economic benefits, but generally family customs and traditional gender roles also play a role. Usually a village only uses a mobile phone, which may be owned by a teacher or missionary, but all members of the village can make the necessary calls. 

 

Ad hoc:

Ad hoc means temporary. An ad hoc network is a group of wireless mobile computers (or nodes) in which each node cooperates by forwarding data packets to each other to allow the nodes to communicate outside the direct wireless transmission range.

 

Network:

A computer network or data network is a telecommunications network that allows computers to exchange data. In computer networks, networked computing devices transfer data to each other over data connections (network links). The data is transmitted in the form of data packets. The connection between the nodes is established by wired means or wireless means. The most famous computer network is the Internet.

The network computing equipment that initiates, routes, and terminates data is called a network node. Nodes can include hosts such as people, phones, servers, and network hardware. When a device can exchange information with another device, regardless of whether they are directly connected to each other, it can be said that two of these devices are networked. The computer network differs in the transmission medium used to carry its signals, the communication protocol used to organize network traffic, network scale, topology, and organizational intent. In most cases, communication protocols overlap (i.e. they use) other more specific or general communication protocols, except for the physical layer that directly deals with the transmission medium.

Computer network support applications, such as access to the World Wide Web, shared servers, printers and fax machines, and use of e-mail and instant messaging applications. A network is a group of two or more interconnected computer systems. There are many types of computer networks, including:

• Local Area Network (LAN)-Computers are geographically close together (that is, in the same building).

• Wide Area Network (WAN)- Computers are further separated and connected by telephone lines or radio waves.

• Camp Network (CAN)-Computers are located in a limited geographic area, such as a campus or military base.

• Metropolitan Area Network (MAN)-A data network designed for towns or cities.

• Home Area Network (HAN) - A network contained in a user's home, used to connect personal digital devices.

Saturday, September 04, 2021

Effects of mobile phones on human body

Introduction

The rapid development of mobile phones in India started around 1980s. At that time it was popularly known as first generation mobile phones that allowed transmitting sound only using analogue technology. Digital transmission i.e. GSM (Global System for Mobile Communication) started around 1990s. This is known as second generation (2G) mobile communication. Apart from voice transmission GSM facilitates internet accessing such as email, fax etc. For both analogue and digital mobile phones, the signal transmitted and received are in the form of waves in radio frequency (RF) and microwave parts of electromagnetic spectrum.

In the year 2000, several reports have reviewed relevant studies and summarized current knowledge about mobile phones and health. The aim of this article is to combine the available epidemiological evidence to learn whether exposure to RF and microwave radiation from mobile phones and their base station can affect health.

Communication Technologies and Radiation

GSM phones transmit around 900 MHz frequency are now-a-days replaced by UMTS phones that transmit around 2.1 GHz = 2.1 billion cycles per second. Health and behavior studies conducted on 3G (third generation) UMTS frequencies likely to be outdated 4G and 5G became widely available.

Radiation is a combination of electric and magnetic energy that travel through space at speed of light. It is also referred to as electromagnetic radiation. Basically radiation is categorized into two basic types.

(i) Ionizing radiation (IR) : This radiation is capable of causing changes in atoms or molecules in the body that can result in tissue damage such as cancer. Example of IR includes X-rays and gamma rays.

(ii) Non-ionizing radiation (NIR): This radiation doesn’t cause any changes in human body, rather it can prompt molecules to vibrate. This can raise the temperature in the body as well as other effects. Example of NIR includes ultraviolet radiation like sunlight, visible light, light bulbs, microwave energy, GSM UMTS transmission and radio frequency energy.

Radiation Effects from Mobile Phone:

The mobile phone system is just like a two-way radio system where one side is individual handset and other side is a base station. The mobile device has a radio receiver and a transmitter and that base station antenna are mounted high off the ground. Mobile phone base station emits relatively constant level of RF radiation. When you make a call the phone uses RF radiation via its antenna to talk to nearby base station. The emission of RF by cellphone at that time depends on three things:

· How long we use the phone

· How close we hold the phone to our body

· How close we are to the base station

According to World Health Organization (WHO) radiations by mobile phones and base stations can break chemical bonds or cause ionization in human body. Federal Communication Commission (FCC) also suggests cell phone users to keep a minimum of 20 cm distance between your mobile phone and your body to significantly reduce radiation effects.

Risks that can Occur:

Evidence so far suggests that mobile phones aren’t harmful still then constant use of cellphones can cause following risks.

1. Generate negative emotions: While two or more persons are talking face to face and in between that if anyone gets a call and get busy talking over phone; this creates negative feelings towards the person who has his or her device visible.

2. Negative effects on stress level: The constant ringing, vibrating alert and reminders can put cellphone user can have negative effects on stress level.

3. Increase risk of illness in your immune system: The constant touching of your cellphone can harbor germs on your handset.

4. Increase risk of chronic pain: While replaying to any message, cellphones require constant use of hands. This can cause pain and inflammation our joints in hand.

5. Increase risk of eye vision problem: Generally cellphone screens are smaller than computer or laptop screens; therefore it needs more stress and strain on your eyes while reading messages.

Precautions to be taken:

Cellphones are the integral part of our day-to-day life. Therefore different scientific reasons are there to treatas precautions while using it so that we can reduce exposes to RF radiation.

· While purchasing a cellphone check out how much radiation your phone emits by looking at its SAR (Specific Absorption Rate) which is a measure of amount of radiation absorbed by your body. SAR is defined as the power absorbed per mass of tissue, measured in watts per kilogram (W/Kg).

· Limit the number of calls you make.

· Restrict the length of your call.

· Use hand-free devices such as wired cellphone devices such as headsets or wireless ones like Bluetooth. Bluetooth and wired headsets are classified as low-power, no licensed radio frequency devices by FCC.

· If you are not using a hands-free device, put the loud speaker on and hold the phone away from your ear.

· Avoid carrying your phone in switch on mode in your pocket, on your belt or anywhere closer to your body since cellphones emit radiation.

· Use alternate side of cellphone while speaking.

· Text message instead of talking.

Search Aptipedia