Abstract

Wireless communications is the transferring of information between two or more points which are not physically connected. Distances can be short, which is used for television remote control and even far distance which is used for deep-space radio communications. The paper deals with the evolutions of technologies and its advantages and comparative study on 3g, 4g, 5g and 6g and overview of 6g technology.

1. INTRODUCTION TO MOBILE TECHNOLOGY

As Mobile technology is technology which is portable. A variety of tasks can be performed at anytime and anywhere. It allows those tasks to be performed via cellular phone, vehicles, and laptops. GPS route framework, a web browser, and instant messenger framework, a video gaming framework. There are numerous transmissions medium like radio wave, microwave, infra-red, GPS and Bluetooth is utilized to exchange of information by means of voice, content, video, 2-dimensional barcodes and the sky is the limit from there. Technology is progressively its request in numerous organizations and individuals' close to home utilize particularly versatile innovation.

Advantages
• Access speed
• Higher Efficiency
• Reduced Cost of Operations
• Endless Possibilities
• Increase Availability of Social Networks

Disadvantages
• Mobile devices expose valuable data to unauthorized people if the proper precautions are not taken to ensure that the devices and the data which is accessed are kept safe.
• Digital Divide among Patients
• Security Issues
• Lack of Information Control
• Safety and privacy

2.COMPARISON OF VARIOUS TECHNOLOGIES
A. Comparison Between 1G, 2G/2.5G and 3G Technologies

Features	1G	2G/2.5G	3G
Deployment	1970-1984	1980-1999	1990-2002
Bandwidth	2 kbps	14-16kbps	2 Mbps
Technology	Analog Cellular	Digital Cellular	Broadband/CDMA/IP Technology
Service	Mobile Telephony	Digital Voice, Short Messaging	Integrated High Audio, Video and Data
Multiplexing	FDMA	TDMA/CDMA	CDMA
Switching	Circuit	Circuit / Circuit for Access N/W and Air Interface	Packet except for air interface
Core Network	PSTN	PSTN	Packet Network
Handoff	Horizontal	Horizontal	Horizontal

B. Comparison between 4G and 5G Technologies

Features	4G	5G
Deployment	2000-2010	2014-2015
Bandwidth	20 Mbps	>1Gbps
Technology	Unified IP & Seamless combo of LAN/ WAN/WLAN /PAN	4G+WWW
Service	Dynamic Information Access, Variable Devices	Dynamic Information Access,Variable Devices with AI capabilities
Multiplexing	CDMA	CDMA
Switching	All Packet	All Packet
Core Network	Internet	Internet
Handoff	Horizontal & Vertica	Horizontal & Vertica

3. WIRELESS NETWORKS

6G is proposed to integrate 5G with satellite networks for global coverage. 6g technology is considered to be cheap and Fast Internet Technology. It provides high data rates and fast Internet speed to access on air through wireless and mobile devices with data ranges up-to 11 Gbps when travelling far distances. The goal of 6g technology is to provide multimedia, internet connectivity and weather information services to the mobile users. Nano Antennas which is designed is implemented at different geographical locations like along roadsides, villages, malls, airports, hospitals to broadcast high speed electromagnetic signals. The globe is decorated by fly sensors with the help of 6G technology. They will provide information to their remote observer station. The point-to-point wireless communication networks transmit super- fast broad band signals through the air at high-speed optical fibres lines to transmit the secured information from transmitters to destinations.

A. 5G Technology

5G technology refers to fifth generation technology, which was started in 2010. It provides up-to 25Mbps connectivity speed. It supports the virtual private network. The speed of uploading and downloading the file is very high. It consumes low battery and strong bandwidth up-to 40 MHz. It is cheap in rates and can be used by multi user. 5G is complete wireless communication with no limitations.

Features
• Faster response time
• High capacity
• Wider range of applications
• Connectivity Speed up-to 25 Mbps
• More software option to upgrade
• Large broadcasting
• Less traffic
• Bi-directional, large bandwidth
• Supports virtual private network

Advantages
• High resolution and bi-directional large bandwidth shaping.
• Technology to gather all networks on one platform.
• More effective and efficient.
• Technology to facilitate subscriber supervision tools for the quick action.
• Most likely, will provide a huge broadcasting data (in Gigabit), which will support more than 60,000 connections.
• Easily manageable with the previous generations.
• Technological sound to support heterogeneous services (including private network).
• Possible to provide uniform, uninterrupted, and consistent connectivity across the world.

Disadvantages
• High cost
• Research
• Infra structure
• Security issues
• Technology is still under process and research on its viability is going on.
• The speed, this technology is claiming seems difficult to achieve (in future, it might be) because of the incompetent 5G

Challenges
i) Technical Challenges
ii)Common Challenges
B. 6G Technology

6g technology refers to the sixth generation technology. It is proposed to integrate 5G technology for a global coverage. For resource monitoring and weather information multimedia video and high-speed Internet connectivity and the Earth imaging satellite networks are used. To integrate these three kinds of satellite like telecommunication, navigation, multimedia networks which provide global positions, internet connectivity with high speed and for mobile user’s weather information services are major three objectives for 6g technology

Advantages
• Ultra-fast to access Internet.
• Data rates up to 10-11 Gbps.
• Home automation and other related applications
• Smart Homes, Cities and Villages.
• Used in the production of Energy from galactic world.
• Space technology and Défense applications will be modified with 6G networks.
• Home based ATM systems.
• Satellite to Satellite Communication for the development of mankind.
• Natural Calamities will be controlled with 6G networks.
• Sea to Space Communication

4. COMPARISON BETWEEN 5G AND 6G TECHNOLOGES

Features	5G	6G
Year	2015	After 5G onwards
Speed	1Gbps and Higher	10 to 11Gbps
Technology	4G+WWW	5G+Satellite
Standards	WiMAX LAS CDMA, OFDM, MC-CDMA, UWB,Network-LMDS, IPv6	GPS, COMPASS, GLONASS, Galileo systems
Core Network	Internet	Internet
Handoff	Horizontal & Vertica	Horizontal & Vertica

5. CONCLUSION

Today mobile phones consist of everything ranging from the smallest size, largest phone memory, speed dialling, video player, audio player, and camera and so on. Recently with the development of internets and Bluetooth technology data sharing has become a child's play. The 6th generation (6G) wireless mobile communication networks integrate satellites for global coverage. It can be a combination of nanocore and artificial intelligence, where all the network operators will be connected to one single core. As in evolution and explosion, many will become extinct but some will change the world. In 6G the cost of mobile call will be relatively high but in 7G this problem will be improved and the cost of call will be reduced and lower-level user will be benefited.

Measurements of trees’ impact on 5G transmissions could prove vital to using a new class of signal.

As 5G technology gets fully implemented over the next several years, cellphones and other wireless tech will grow more powerful with increased data flow and lower latency. But along with these benefits comes a question: Will your next-generation cellphone be unable to see the forest for the trees?

That’s one way to describe the problem confronting cell network designers, who have to embrace both the benefits and shortcomings of a new class of signals that 5G will use: millimeter waves. Not only can these waves carry more information than conventional transmissions do, but they also usefully occupy a portion of the broadcast spectrum that communication technologies seldom use — a major concern in an age when broadcasters vie for portions of spectrum like prospectors staking out territory.

However, millimeter waves also have drawbacks, including their limited ability to penetrate obstacles. These obstacles include buildings, but also the trees that dot the landscape. Until recently little was known about how trees affected millimeter wave propagation. And just as few of us would want to imagine a landscape without greenery, few designers would be able to plan networks around it without such a crucial fundamental detail.

For one type of leafy tree, the European nettle, the average attenuation in summer was 27.1 dB, but it relaxed to 22.2 dB in winter when the tree was bare. Evergreens blocked more of the signal. Their average attenuation was 35.3 dB, a number that did not change with the season.

(As a measure of comparison, the team also looked at different types of building materials. Wooden doors, plasterboard walls and interior glass showed losses of up to 40.5 dB, 31.6 dB and 18.1 dB, respectively, while exterior building materials exhibited even larger losses, up to 66.5 dB.)

While NIST’s contributions to 5G network development effort could end up as ubiquitous as trees themselves, for most of us they will be considerably less visible. The measurements the team made are intended mainly for companies that create models of how different objects affect millimeter waves. Part of the effort was a collaboration with Ansys Inc. The company used the measurement data NIST shared with it to tune the tree simulation models, which cell companies use to plan out their networks of antennas in detail.

“Most models don’t include measurement-based information about trees,” said NIST’s David Lai, one of the scientists who conducted the study. “They might simply say that for a given tree-like shape, we should expect a certain amount of signal loss. We want to improve their models by providing accurate measurement-based propagation data.”

NIST’s collaboration with Ansys contributed to guidance issued by the International Telecommunication Union (ITU), the organization that creates guidelines for telecom standards. The results now appear as a new section on trees in ITU’s Recommendation ITU-R P.833-10. This publication serves as a reference for signal propagation models, which others will develop.

“Our goal is to get these measurements in front of the entire wireless community,” Golmie said. “We hope this effort will help the entire marketplace.”

The National Institute of Standards and Technology (NIST) has set out to solve this problem by measuring trees’ effect on millimeter waves. The effort could make a profound difference in our next-generation devices’ ability to see the 5G antennae that may soon sprout.

The 5G era will feature wireless communication not only between people but also between devices connected to the Internet of Things. The increased demand for larger downloads by cell customers and lag-free network response by gamers has spurred the wireless industry to pursue speedier, more effective communication. Not only could our current devices and services work more effectively, but we could realize new ones: Autonomous vehicles will depend on such quick network response to function.

“We will be able to do new things if our machines can exchange and process information quickly and effectively,” said Nada Golmie, head of NIST’s Wireless Networks Division in the Communications Technology Laboratory. “But you need a good communication infrastructure. The idea is to connect, process data in one place and do things with it elsewhere.”

Millimeter waves, which are new turf for the wireless industry, could be part of the solution. Their wave crests are just a few millimeters apart — a very short distance compared with radio waves that can be several meters long. And their frequencies are very high, somewhere between 30 and 300 gigahertz, or billion wave crests per second. Compared with conventional radio transmissions, which are in the kilohertz (for AM) and megahertz (for FM) ranges, new 5G signals will be very high frequency indeed — something like a bird tweeting at the upper range of human hearing compared with radio’s deep, low bass.

It is millimeter waves’ high frequency that makes them both tantalizing as data carriers and also hard to harness. On the one hand, more wave crests per second means the waves can carry more information, and our data-hungry era craves that capability to provide those faster downloads and network responses. On the other, high-frequency waves have trouble traveling through obstructions. Anyone who has passed near a house or car whose occupants are playing loud dance music knows that the throbbing bass frequencies are most of what reaches the outdoors, not the treble of a lilting soprano.

For 5G networks, the obstructing wall can be no more than an oak leaf. For that reason, NIST scientists embarked on a somewhat unusual task in September 2019: They set up measurement equipment near trees and shrubs of different sizes around the agency’s Gaithersburg, Maryland, campus. The study continued for months, in part because they needed seasonal perspective.

“The tree study is one of the few out there that looks at the same tree’s effect on a particular signal frequency through different seasons,” Golmie said. “We couldn’t only do the survey in the winter, because things would have changed by summer. It turns out that even the shape of leaves affects whether a signal will reflect or get through.”

The team worked with the wireless community to develop the mobile equipment that was needed to take the measurements. The researchers focused it on single trees and aimed millimeter-wave signals at them from a range of angles and positions, to simulate waves coming from different directions. They measured the loss, or attenuation, in decibels. (Each 10 dB of loss is a reduction by a power of 10; a 30 dB attenuation would mean the signal is reduced by a factor of 1,000.)

The massive benefits of 4G technology is already experienced by the todays community and the technological innovations are ready to bring the more sophisticated and wonderful experience in communication technology in the name of 5G technology. On this time, it is essential to bring out few important merits of 5G technology. Fifth generation cellular networks (5G) brings new opportunities and have wide capabilities to provide various services to an individual to organization and society. Significantly 5G will improve the network connection and delivers groundbreaking solutions to the society by connecting billions of devices. 5G technology delivers high speed data services with reduced latency with increased reliability. The massive network capacity and resource availability provides uniform experiences to the users.

The real time information sharing with lag free experience can help to avoid critical factors in live saving applications to simple road accident managements. 5G provides services on the same radio frequency that is being used for smart phones, Wi-Fi networks and satellite communications. However, the technology brings the facilities in a broader way than what we are using now.

WHERE IS 5G BEING USED?

Broadly speaking, 5G is used across three main types of connected services, including enhanced mobile broadband, mission-critical communications, and the massive IoT. A defining capability of 5G is that it is designed for forward compatibility—the ability to flexibly support future services that are unknown today.

1. Enhanced mobile broadband
• In addition to making our smartphones better, 5G mobile technology can usher in new immersive experiences such as VR and AR with faster, more uniform data rates, lower latency, and lower cost-per-bit.
2. Mission-critical communications
• 5G can enable new services that can transform industries with ultra-reliable, available, low-latency links like remote control of critical infrastructure, vehicles, and medical procedures.
3. Massive IoT
• 5G is meant to seamlessly connect a massive number of embedded sensors in virtually everything through the ability to scale down in data rates, power, and mobility—providing extremely lean and low-cost connectivity solutions

HOW DOES 5G WORK?

Like 4G LTE, 5G is also OFDM-based (Orthogonal frequency-division multiplexing) and will operate based on the same mobile networking principles. However, the new 5G NR (New Radio) air interface will further enhance OFDM to deliver a much higher degree of flexibility and scalability.

5G will not only deliver faster, better mobile broadband services compared to 4G LTE, but it will also expand into new service areas, such as mission-critical communications and connecting the massive IoT. This is enabled by many new 5G NR air interface design techniques, such as a new self-contained TDD sub frame design.

HOW FAST WILL 5G TAKE-UP BE?

The projected adoption rate for 5G differs drastically from all previous generation networks (3G, 4G).

While previous technology was driven by mobile internet usage and the availability of “killer apps,” 5G is expected to be mainly driven by new IoT usages, such as connected and self-driving cars, for example.

Globally, the number of 5G users worldwide is foreseen to explode from less than 200 million in 2019 to 1,02 Billion in 2023 (Fortune Feb. 2020).

According to a November 2020 report from Ericsson, 5G will reach 3.5 billion subscriptions by 2026, making it the fastest generation ever to be rolled out on a global scale.

WILL 5G TECHNOLOGY BE SECURE?

4G networks use the USIM application to perform strong mutual authentication between the user and his/her connected device and the networks.

• The entity hosting the USIM application can be a removable SIM card or an embedded UICC chip.
• This strong mutual authentication is crucial to enable trusted services.
• Today, security solutions are already a mix of security at the edge (device) and security at the core (network).
• Several security frameworks may co-exist in the future, and 5G is likely to re-use existing solutions used today for 4G networks and the cloud (SEs, HSM, certification, Over-The-Air provisioning, and KMS).
• The standard for strong mutual authentication for 5G networks was finalized in 2018.
• The need for 5G security, privacy, and trust will be as strong as for 4G, if not stronger, with the increased impact of IoT services.
• Local SEs in devices can secure network access and support secure services such as emergency call management and virtual IoT networks.

So as of now, few countries tested and started their 5G services and developing countries are in queue to improve the communication standards to start 5G services. Let’s welcome the new technology and make use of it for good things.