Fast and seamless communication is in great demand in contemporary world. People need to have the capability to communicate with each other at any place and at any time. The growing need for wireless communication technology has led to the need for faster and more reliable mobile communication standards.
Intensive advancements in wireless network technologies resulted in the most comprehensive system of mobile communication technology. This system technology is labeled the fourth generation (4G) mobile technology. This paper aims to trace the evolution of 4G wireless technology and determine its key benefits and possible hazards and complications as compared to its predecessors, as well as outline the trends of its further development.
What is Fourth Generation Wireless (4G)?
4G is an abbreviation for the fourth generation of mobile communication standards, which comes after the third generation (3G). The premise behind the 4G is an advanced IP-based technology, which allows delivering rich multimedia data and services to users with a fast speed, high quality of service (QoS), and improved security in any place and at any time (Janssen, n.d.).
4G is designed to provide the speed 10 times higher than that of any modern 3G technology. With such high rates of data transfer, mobile devices can be comparable to personal computers offering equal multimedia and gaming capabilities (Ganapati, 2010).
Seamless mobility and interoperability with current mobile standards are important features of 4G technology. According to Janssen (n.d.), “Implementations will involve new technologies such as femtocell and picocell, which will address the needs of mobile users wherever they are and will free up network resources for roaming users or those in more remote service areas.”
Two distinct standards were introduced in 2009 as candidates for becoming the fourth generation of telecommunications. The first one is LTE Advanced (Long Term Evolution) (Pica, 2014). The second is 802.16m, as standardized by IEEE (Institute of Electrical and Electronics Engineers), but commonly referred to as WiMax (Janssen, n.d.). Both standards attempt to achieve high efficiency, capability of dynamic allocation of network resources in a cell, high QoS, and they are based on an all-IP standard.
WiMax is believed to be the first 4G standard. It uses BWA (broadband wireless access) IP technology. Current development of WiMAX and LTE is mainly a temporary solution, while WiMAX 2, which is also designed on the 802.16m, and LTE Advanced are considered as final objectives. They attempt to meet the requirements of The International Telecommunications (ITU) for 4G in terms of throughput, security, and stability (Janssen, n.d.). The question whether current level of these two standards is good enough for them to be regarded as 4G is widely discussed.
The ITU states that LTE is more comparable to the anticipated standards of 4G than WiMax. In fact, the latter is a part of the 3G technology, but Sprint labels WiMax as real 4G. Nevertheless, the speed WiMax can provide is comparable to current speed of LTE. WiMax is supported by IEEE, while LTE has been designed by an association of cellular carriers.
Another distinction between these standards is that the implementation of WiMax involves creating new networks, while LTE has evolved on the basis of CDMA/HSPA networks (Ganapati, 2010). Currently, LTE is mainly used by Verizon and AT&T carriers, while Sprint is moving towards WiMax.
The Evolution of Wireless Generations
The evolution of wireless technology is divided into four main generations. The first generation used analog systems and was designed to transmit only voice (Ganapati, 2010).
In fact, there was no need to transmit any other data besides analog voice signals at that time. However, there were modems that could connect via 1G networks, but the wireless connections were much more susceptible to noise than traditional wired networks and operated at incredibly low speed. Even if they had been faster, there were not many devices capable of receiving such amount of data (Ziegler, 2011).
The second generation adopted digital broadcasts and provided the possibility to exchange data, but the main focus remained on voice calls. There are two standards used by 2G cellphones: GSM and CDMA (Ganapati, 2010). These standards had a range of advantages over 1G systems, such as more clear sound quality and higher security. Even though the characteristics of those standards were still very low, the systems are considered authentic and revolutionary.
Nevertheless, these innovative standards did not have essential strongly connected support for their services. 2G networks provided support of text messaging and circuit-switched data (CSD), which made it possible make digital calls with data transfer speed of 14.4 kbps. It was not purely digital connection as users still had to place calls. That technology worked similarly to dial-up modems: users could either make calls or use the Internet. In addition, the cost of CSD services made it unpractical for public use (Ziegler, 2011).
2.5G was an intermediate stage of wireless technology between the second and the third generations. A new standard, GPRS, appeared. It had provided better transmissions and soon advanced to the EDGE system, which allowed up to 400 kbps speed. EDGE standard is still popular in many countries today (Ganapati, 2010). In addition, GPRS changed the pricing system as carriers began charging by amount of data rather than by the time.
The advent of GPRS was significant but did not as much to claim the title of new generation technology. The reason for this was that ITU had already published the review of requirements for standards to be classified as a “true” 3G. Some of these specifications estimated that technologies should have stationary speeds of 2 Mbps and mobile speeds of 384 kbps, a data rate, which was not close to the maximum capabilities of GPRS (Ziegler, 2011).
There is no single opinion on which standards belong to 3G. In general, experts define 3G systems based on their speed (2 Mbps). Sprint and Verizon have a system called EVDO, while AT&T and T-Mobile utilized a system HSDPA. A more advanced evolution, HSDPA+, offers data transfer speeds of up to 14 Mbps (Ganapati, 2010). Besides speed requirements, the ITU’s appealed that 3G systems should offer smooth transfer paths from 2G networks. In that regard, new standards appeared, UMTS and CDMA2000 that were supported by GSM and IS-95 carriers respectively (Ziegler, 2011).
The first 3G networks appeared in 2001 and were implemented rather slowly due to high costs of the hardware upgrades and spectrum. Thus, some carriers were holding to 2G networks by implementing EDGE. Different experts have opposite views on where to place EDGE within this generation framework. It is not fast enough to constitute a 3G, but it is about two times faster than GPRS, a 2.5G system. Some people refer to it as a 2.75G but according to the ITU, EDGE is officially a 2G standard capable of building up to 3G speed.
The next step of evolution of CDMA2000 was an EV-DO Revision A. It had quite faster download speed and much faster upload speed. At the same time, UMTS evolved into HSUPA, and was later upgraded to HSPA+ and HSPA+ Evolution. In theory, both network standards could achieve speeds ranging from 14 Mbps to 600 Mbps. Once again, experts could not reach agreement on whether these standards are 3G, 3.5G, 3.75G or something else (Ziegler, 2011).
The requirements for 4G were established by ITU-Radio in terms of bandwidth, spectral effectiveness, and a set of other technical specifications in 2008. For users, the most important specification was the maximum speed of 100 Mbit/s for high mobility devices, for example while driving, and of 1 Gbit/s for low mobility devices. For comparison, the average download speed using current networks ranges closely to 10Mbit/s.
The problem is that ITU-R sets standards but cannot control their implementation. Thus, only in 2010, the ITU evaluated six technologies to determine whether they match the specifications of “true” 4G. As the result, LTE-Advanced and WirelessMAN-Advanced (WiMax) were acknowledged to meet the requirements of the ITU.
LTE-Advanced constitutes to 4G not only due to its speeds but also due to considerable advances in the network infrastructure. The standard aims to increase transfer rate by utilizing a combination of conventional macro cells and greatly enhanced small cells. The main objective is to provide coverage of higher quality and greater throughput.
At the same time, the transmitters have to be working on different frequency bands, so that there is no interference. In addition, LTE-A has two more important features, MIMO and CoMP, that increase bandwidth, speed, and stable connection during high mobility of the receiver.
However, the current state of LTE-A, HSPA+ and WiMAX was not providing all the above-mentioned specifications, but the ITU recognized them as 4G systems under the pressure of many companies that had already started investing funds in these networks (Triggs, 2013).
International Telecommunications Union (ITU)
The ITU is an agency of the United Nations and its standards are set for the whole world. The ITU coined the terms 3G (Van Camp, 2011). The radio department of the ITU set the standards for 4G, which are referred to as International Mobile Telecommunications Advanced (IMT-Advanced).
An IMT-A mobile system is supposed to support secure cellular services with high mobility and data rate of 100 Mbps and above, which is required to receive streaming multimedia data. Cuurent 3G technologies WiMAX and LTE do not meet such requirements. However, most of the systems labeled as 4G do not satisfy all IMT-Advanced requirements, as well (Janssen, n.d.).
4G has significantly better performance than WiFi or 3G in terms of bandwidth and loss of packages rates. In addition, by enhancing network diversity, 4G systems can employ multi-path TCP in order to allow high mobility without breaks.
In terms of mobility, 4G aims to eliminate packet-switched communications and circuit-switched telephony service (Chen, Towsley, Nahum, Gibbens, & Lim, 2012). It can be achieved by using IPv6. Previously used protocol, IPv4, has a limited number of IPs that can be given to receivers. IPv6 can support a much greater amount of IP addresses, and will be effective in sustaining a smooth connectivity for users (What’s a G?, n.d.).
The throughput in 4G networks is attained by using a technology called OFDM (Orthogonal Frequency Divison Multiplexing). It not only decreases latency (time required to establish connection) but also prevents many interferences and is capable of transmitting bigger loads of content through the same bandwidth.
In other words, OFDM allows 4G devices to stream higher quality content than ever, mainly because 4G has been ultimately aimed at transmitting data rather than voice calls. Moreover, 4G standards use TCP/IP protocols, which are standard protocols for the Internet. Even greater speed can be attained by using MIMO technology, which involves uses many antennas similar to Wi-Fi gear.
Nokia has reached a speed of 173Mbps using 2×2 MIMO setup (the transmitter and receiver equipped with 2 antennas each), so a 4×4 setup could theoretically achieve twice the throughput of the 2×2 (Rogerson, 2014).
Cell Phone Towers and Antennas
4G transmits data using standard Internet protocol, which functions by breaking content into packets on transmitting end and compiling these packets on the receiving end. The data in these packets can travel through different networks without being distorted.
Before transmitting or receiving and packets, a device has to be connected with a base station, which I also called a cell phone tower. Cell tower have all needed antenna equipment to transfer packets to and from a device (Chandler, 2012).
4G offers bigger capacity, so that it can provide connection to a higher amount of users simultaneously. One 3G cell tower can have about 60 to 100 users connected at the same time without losing signal and speed. An LTE tower can provide connection to 300-400 users (Chandler, 2012). Mobile operators use new radio spectrum to overlay LTE networks.
This process requires some supplementary equipment, as well as improvement of existing technology, such as the replacing old radio equipment with new one of the smaller dimensions, and strengthening antenna panels (Marshall, 2014).
4G has some distinctive features of their cell sites functioning. One of the most important features is MIMO (multiple input multiple output). It allows stations and devices exchange information via multiple antennas.
MIMO is implemented in LTE only for the downlink and only using a maximum of four transmitters in the station and four receivers in the mobile device. With LTE-Advanced, MIMO will allow working on eight antennas on each side and for both upload and download streams.
MIMO has two objectives. When a device is located in noisy radio environment, MIMO starts the multiple antennas working together to focus the signals in one precise direction. Thus, the signal becomes stronger without increasing the power of transmission. In case the signals are strong and the environment is not noisy, MIMO can produce higher data rates or support a greater number of users.
The system named spatial multiplexing allows establishing many data streams simultaneously over the same frequencies. For example, a cell tower with eight transmitters can transmit eight signals at the given time to a mobile device that is equipped with eight receivers. Each stream is received by device at a little different angle and time, thus, processing procedures in the device сan combine these characteristics and sort out the original streams.
Another significant LTE feature is relaying, which lengthens coverage to areas with bad signal. Traditional relays work according to a relatively simple mechanism. They receive transmission, intensify it, and send it further.
4G use more advanced relays, which decode the signals and then send only those intended for the devices that the particular relay is serving. This technique diminishes interference and increases the capacity of users linked with the relay (Bleicher, 2013).
Additionally, 4G can utilize DAS (Distributed Antenna Systems), which can be mounted in crowded areas such as stadiums, malls, office centers, bus stations, and airports in order to add to the capacity when many people are trying to access the wireless network (Pica, 2014).
Wireless Devices and Health Concerns
3G allowed people browsing the web on phones or tablets. 4G provided even greater opportunities, such streaming high-quality multimedia on mobile devices. However, the disadvantage of 4G is that it needs more bandwidth its predecessors, which results in greater exposure to radiation. Implementation of 4G network requires additional and more powerful towers. Many people believe that these towers are emitting significantly more radiation than ever. Therefore, 4G technology is important issue of discussion for health care providers (Viswanathan, n.d.).
In addition to new towers, the developers of 4G had to achieve greater bandwidth in 4G devices, so they designed “smart antennas,” which are sets of 4 antennas in one device. There have been a constant debate on potential carcinogenic effects of mobile phones, and experts claim that greater amount of antennas can multiply these negative effects (Miller, 2013).
Some studies point that several people who live or work near cell phone towers complain about the unexpected occurrence of headaches, nausea, blurred vision, and even a tumors. Healthcare experts indicate that rates of such cases have been increasing over the past decade since the beginning of 3G and Wi-Fi implementations. Moreover, experts are concerned that 4G towers may result in even stronger effects.
However, there is no definite evidence to confirm the hazards of wireless stations and devices to human health. Main mobile providers that offer 4G networking are pointing out to the lack of credible medical research to prove the negative effects of cell stations. In addition, they state that their technology has undergone serious and thorough tests and corresponds to all international safety standards (Viswanathan, n.d.)
In addition, many mobile providers argue that building fewer cell towers would have even worse outcomes than building more of them. They claim that more towers will only slightly increase the radiation. On the contrary, decreasing the amount of towers would make transmissions weaker. Consequently, this would make each station emitting greater output, which could ultimately constitute to much more damaging effects (Viswanathan, n.d.)
Companies Leading the Way
Verizon was the first carrier to introduce LTE. However, it tends to underperform as the speeds it offers are steadily decreasing since it provides services to over 40 million LTE devices. In some areas, the LTE networks become so overloaded that they switch users to 3G. However, Verizon has recently completed its new base station of 4G, and it began constructing another much more powerful one. The first site is focused on coverage, while the second one will boost capacity in the largest cities where the amount of users is the most concentrated.
In such cities, as New York, Chicago, Los Angeles, and others, Verizon has constructed additional 20-40 MHz systems, increasing 4G networks capacity. Such build-up allows Verizon serving tens of millions additional LTE users without overloading its networks. As for the speed, the tests showed download speed to reach 80 Mbps, however, it will decrease with time due to influx of new customers (Fitchard, 2014).
At the beginning of the 4G era, Sprint was a leading provider with the network coverage of 36 largest cities (Ganapati, 2010). Sprint’s 4G network is labeled Spark. In 2013, the carrier launched the new tri-band system but currently, Spark has not many reasons to be proud. Sprint is promotion Spark as an innovation in mobile communication, which unites three different bands in a single “super-LTE system” (Fitchard, 2014).
In fact, Spark does not provide access to all three LTE systems, but only two of them. Its basic 4G system is the PCS network. Additional system is the 2.5 GHz airwaves. The third broadband is the 800 MHz system and it will not be available until the end of 2014.
The tri-band Spark does support carrier aggregation. It means that it does not splice bands together but rather runs them separately. Users can connect to only one of the networks but not all at the same time. Marketing campaigns claim having 50 Mbps on Spark, but this is the maximum speed. On average, Spark can offer from 6 to 12 Mbps. Sprint currently has the lowest mobile broadband, the lowest capacity, and the narrowest coverage in the U.S. (Fitchard, 2014).
When the competitors were rapidly developing 4G networks, T-Mobile was not in a hurry. In fact, it had to make its 3G network work properly (Ganapati, 2010).
However, recently, the provider has a lot to brag about in 4G development. T-Mobile created its national LTE network from the ground up in just 8 months, and recently doubled its capacity in over 40 largest cities.
T-Mobile’s has technology of approximately similar capabilities as AT&T and Verizon. However, T-Mobile is much smaller, meaning that the bandwidth is distributed between smaller amounts of subscribers and thus, offers higher speeds than its competitors.
Thus, T-Mobile has an powerful base, and it will most likely grow bigger in 2015. It plans to increase its broadband capacity twice as much as it has now, and expand to up to hundred new cities allowing T-Mobile to compete with Verizon on equal terms. The drawback of T-Mobile is its lacking coverage outside of the big cities. Therefore, in the nearest future, the provider will focus on enhancing capacity in order to provide services and high speed to millions of new customers (Fitchard, 2014).
AT&T is not so keen on deploying 4G networks. It has resources and coverage but focuses on 2G and 3G capacity for LTE. AT&T does not offer the highest speed of networking, but can allocate more bandwidth for its subscribers. In addition, AT&T is employs new technologies such as small cells and self-optimizing networks (SON).
As is seen from AT&T’s marketing, it shifted focus from speed to reliability. While T-Mobile and Verizon offer impressively high speeds, many customers still prefer medium speed but with a steady, uninterrupted connection (Fitchard, 2014).
What Comes After 4G?
LTE-Advanced and the Future of 4G
The world is only beginning adopting 4G but some regions are already thinking of the new generation of mobile networks. The next step is LTE-Advanced. Basically, the main principle of is increasing the amount of antennas, alongside carrier aggregation function.
Theoretically, LTE-A will offer much higher speeds than the current 4G standards, surpassing 160 Mbps. LTE-A will not support existing 4G devices. However, there are few of them that are already compatible with LTE-A, such as Korean edition of Samsung Galaxy S5. Nevertheless, the technology is still in its early stage of development, and the networks are working on standard LTE (Rogerson, 2014).
What Is 5G?
5G today is nothing more than a concept. It will obviously be substantially better than 4G. It is believed that customers using a 5G network would be able to download an movie in just one second. According to scientists at Cornell University, 5G will provide a “seamless user experience” (Ripton, 2014). The remarkable speeds will satisfy practically all needs for rich media content. There will be no lag, no long buffering, or synchronizations.
5G is believed to be working on MIMO technology by using many small antennas to create individual streams. As mentioned above, some 4G standards are also using this technology. 5G will also use much more towers, both big sites and smaller stations. Some researchers suggest that 5G base stations could be installed in every home and streetlight.
As for now, the price rates of wireless mobile services have been steadily decreasing. However, Ripton (2014) states, “South Korea’s minister of engineering, science, and technology believes that companies there will spend more than $300bn (£181bn) on 5G technology and infrastructure.” With such huge amount of money invested, the users may expect some increase in service prices.
Based on the normal life cycle of wireless technology development, it is possible to expect the arrival of 5G approximately in 2021. However, it can happen faster. For example, South Korean government has spent $1.5 billion to test a 5G network in 2017. It is anticipated that the whole South Korea can be connected to 5G by 2020. As for the U.S., experts believe that 5G will not appear in America until 2018. Moreover, it will not become major service for networking until 2025 (Ripton, 2014).
The comparison of 4G mobile telecommunication technology and earlier generations has revealed that standards, such as LTE-A and WiMax have substantial advantages over any other standards use before. They provide high-quality speed that enables users stream rich multimedia content and high throughput that allows serving several times more users that any preceding standards. The main objective of current 4G standards development is to achieve specifications established by ITU-R, which include the maximum speed of 100 Mbit/s for high mobility devices, and of 1 Gbit/s for low mobility devices.
Major mobile carriers are constantly improving their networks to provide quality service that meets the above-mentioned requirements while maintaining high stability of connection and accessibility. That is why mobile service providers focus on developing their network coverage by building more cell towers and implementing new features into the existing ones, such MIMO (multiple input multiple output), relaying and DAS (Distributed Antenna Systems) in order to support the growing number of subscribers.
At the same time, such technological expansions raise public concerns regarding the potential negative effects of 4G networks on human health. For now, there has been little evidence to support these claims but health care experts suggest that people may face serious negative health outcomes as 4G networks continue to expand. Anyhow, the advantages of 4G are impressive. However, there is still much to improve in telecommunication technology.
Bleicher, A. (2013). LTE-advanced is the real 4G. Retrieved from http://spectrum.ieee.org/telecom/standards/lte-advanced-is-the-real-4g
Chandler, N. (2012). How 4G works. Retrieved from http://electronics.howstuffworks.com/4g.htm
Chen, Y. C., Towsley, D., Nahum, E. M., Gibbens, R. J., & Lim, Y. S. (2012). Characterizing 4G and 3G networks: Supporting mobility with multipath TCP. School of Computer Science, University of Massachusetts Amherst, Tech. Rep, 22.
Fitchard, K. (2014). The state of LTE in the U.S.: How the carriers’ 4G networks stack up. Retrieved from https://gigaom.com/2014/01/30/4g-vs-4g-comparing-lte-networks-in-the-us/
Ganapati, P. (2010). Wired explains: Everything you need to know about 4G wireless. Retrieved from http://www.wired.com/2010/06/wired-explains-4g/
Janssen, C. (n.d.). What is fourth generation wireless (4G)? Retrieved from http://www.techopedia.com/definition/2920/forth-generation-wireless-4g
Marshall, P. (2014). Mobile broadband and LTE stokes growth in the telecom tower industry.
Miller, Z. C. (2013). 4G/LTE mobile network poses greater chronic health risks than previous incarnations. Retrieved from http://www.naturalnews.com/041561_mobile_network_health_risks_cell_phones.html
Pica, T. (2014). 8 network terms explained. Retrieved from http://www.verizonwireless.com/news/article/2014/04/network-terms-explained
Ripton, J.T. (2014). The 5G network: When will it launch and what will it mean for consumers? The Guardian. Retrieved from http://www.theguardian.com/media-network/media-network-blog/2014/aug/26/5g-network-launch-mobile-consumers-connectivity-download
Rogerson, J. (2014). 4G and LTE: Everything you need to know. Retrieved from http://www.techradar.com/us/news/phone-and-communications/mobile-phones/4g-and-lte-everything-you-need-to-know-926835
Triggs, R. (2013). 4G vs LTE – key differences explained. Retrieved from http://www.androidauthority.com/4g-vs-lte-274882/
Van Camp, J. (2011). 4G explained: A guide to LTE, WiMax, HSPA, and more. Retrieved from http://www.digitaltrends.com/mobile/what-is-4g-the-ultimate-guide-to-4g-wireless-networks-phones-coverage-and-more/
Vilches, J. (2010). Everything you need to know about 4G wireless technology. Retrieved from http://www.techspot.com/guides/272-everything-about-4g/
Viswanathan, P. (n.d.). 3G vs. 4G mobile networks: The health factor. Retrieved from http://mobiledevices.about.com/od/carrierfaq/a/3g-Vs-4g-Mobile-Networks-The-Health-Factor.htm
What’s a G? (n.d.). Understanding 4G technology standards. Retrieved from http://www.whatsag.com/G/Understanding_4G.php
Ziegler, C. (2011). 2G, 3G, 4G, and everything in between: An Engadget wireless primer. Retrieved from http://www.engadget.com/2011/01/17/2g-3g-4g-and-everything-in-between-an-engadget-wireless-prim/