FOCUSED ISSUE FEATURE Wireless Communications: Present and Future Edward C.Niehenke his special issue"Wireless Communi- cations:Present and Future"has been l1135m niationT an explosion of growth.This introduction traces the technology developments to the present.Future wire- transoceanic communication In 1896.Guglielmo Marconi(Figure 1)developed the first wireless telegraph system.In December 1901.he used his system for transmitting the first wireless signals across the Atlantic between Poldhu,Corn- hn Newfoundiand.neo Radio Development Amplitude modulated (AM)radio began with the first experimental broadcast in 1906 by Reginald Fessenden (Figure 2)and was used for small-scale voice and music broadcasts up until World War I.On the evening of 24 December 1906,F lin and read the Bible [21.[31.The increase in the use of Mradio came the following decade The first licensed commercial radio services began on AM in the 1920s. 26 IEEE mcrowave magazine 1527-3342/14/831.00©2014EEE March/April 2014
26 1527-3342/14/$31.00©2014IEEE March/April 2014 Digital Object Identifier 10.1109/MMM.2013.2296207 Date of publication: 7 March 2014 FOCUSED ISSUE FEATURE Wireless Communications: Present and Future Edward C. Niehenke Edward C. Niehenke (e.niehenke@ieee.org) is with Niehenke Consulting, 5829 Bellanca Drive, Elkridge, Maryland 21075 United States. T his special issue “Wireless Communications: Present and Future” has been prepared by members of the IEEE Microwave Theory and Techniques (MTT)-20 Technical Committee, “Wireless Communications.” This area of technology has experienced an explosion of growth. This introduction traces the technology developments to the present. Future wireless communication developments are presented in four articles in this special issue. Transoceanic Communication In 1896, Guglielmo Marconi (Figure 1) developed the first wireless telegraph system. In December 1901, he used his system for transmitting the first wireless signals across the Atlantic between Poldhu, Cornwall, and St. John’s, Newfoundland, a distance of 2,100 miles [1]. Radio Development Amplitude modulated (AM) radio began with the first experimental broadcast in 1906 by Reginald Fessenden (Figure 2) and was used for small-scale voice and music broadcasts up until World War I. On the evening of 24 December 1906, Fessenden used the alternator-transmitter to send out a short program from Brant Rock, which included his playing the song “O Holy Night” on the violin and reading a passage from the Bible [2], [3]. The great increase in the use of AM radio came the following decade. The first licensed commercial radio services began on AM in the 1920s. Image l censed by Ingram Publ i sh i ng i
In 1947,the transistor was invented by scientists John Bardeen, Walter Brattain,and William Shockley frequency modulation (FM)radio 561 Rathe ve to crea the wave instead.FM radio receivers proved to gener tilartothat ate a much clearer sound,free of static,than the AM radio dominant at the time in the late 19th century that showed that radio waves radio era,with a vision that were reflected by metallic objects.This possibility was was ahead of his time母He inve ted the regener seminal work or omagnet5月d 1141ho pleship detection deviceintended to help avoid and the superheterodyne receiver (patented 1918) collisions in fog [10]. In the 1934-1939 period,eight nations developed on of e ependently and n great secr recy,rad ping。hot reat Britain had shared their basic information with KHz.Armstrong mixed the high-f quency sig our Commonwealth countries:Australia,Canada, ver frequency,which was far Zealand,and So uth Africa,and these countries mor a elope dus ra t lab of RADAR”aS the States Signal Corps as an acronym for radio detection March/April 2014 IEEE mcrowave magazine 27
Edwin Armstrong (Figure 3) was one of the most prolific inventors of the radio era, with a vision that was ahead of his time [4]–[8]. He invented the regenerative circuit (invented while he was a junior in college at Columbia University, New York City, and patented 1914), the superregenerative circuit (patented 1922), and the superheterodyne receiver (patented 1918). Armstrong had realized that higher-frequency equipment would allow detection of enemy shipping much more effectively, but at the time, no practical short-wave amplifier existed. In those days “short wave” meant anything above 500 KHz. Armstrong mixed the high-frequency signal down to a lower frequency, which was far more amenable to high-gain amplification using triodes. While working in the basement lab of Columbia’s Philosophy Hall, Armstrong created frequency modulation (FM) radio [56]. Rather than varying the amplitude of a radio wave to create sound, Armstrong’s method varied the frequency of the wave instead. FM radio receivers proved to generate a much clearer sound, free of static, than the AM radio dominant at the time. Radar Development Radar can be traced back to the work of Heinrich Hertz in the late 19th century that showed that radio waves were reflected by metallic objects. This possibility was suggested in James Clerk Maxwell’s seminal work on electromagnetism [9]. Christian Hülsmeyer, the German inventor, built and demonstrated on 9 June 1904 a simple ship detection device intended to help avoid collisions in fog [10]. In the 1934–1939 period, eight nations developed, independently and in great secrecy, radar systems: the United States, Great Britain, Germany, the USSR, Japan, The Netherlands, France, and Italy. In addition, Great Britain had shared their basic information with four Commonwealth countries: Australia, Canada, New Zealand, and South Africa, and these countries had also developed indigenous radar systems. During the war, Hungary was added to this list [11]. The term “RADAR” was coined in 1940 by the United States Signal Corps as an acronym for radio detection Figure 1. Marconi operating an apparatus similar to that used by him to transmit the first wireless signal across the Atlantic in 1901. (Source: Wikimedia Commons.) Figure 2. Reginald Fessenden, the father of radio broadcasting. (Source: Wikimedia Commons.) Figure 3. Edwin Armstrong, the creator of FM radio. (Source: Wikimedia Commons.) In 1947, the transistor was invented by scientists John Bardeen, Walter Brattain, and William Shockley. March/April 2014 27
The GPS project was developed in 1973 [45]to overcome the limitations of previous navigation systems. oCRmna and the transmittod froou cy of the signal (Doppler fre- quency shift)[12.Figure 4 shows a large radar antenna used to track space objects as well as ballistic missiles adar,in a ion to its military applications,ha a sors for occupancy monitoring [13),experimental dem onstration of noncontact pulse-wave velocity moni m&rpcDioplrsensosaswelaS Transistor Invention In 1947,the transistor was invented by scientists John Bardeen,Walter Brattain, and Willia m Shoc ley(Figure 5)who later share t Nobel Prize [15 foundation for the develop ment of modern electron transmitted signal,while the velocity of theobject is deter ics and making possible the marriage of computers mined by the difference between the received frequency and communications. LORAN Navig ships and aircraft to determine their position and speed from low-frequency (LF)radio sig nals transmitted 6 fixe nit.LORAN w radi the toch nology of the British Generalized Estimating Equation (GEE)radio navigation system that was used early in World War IL It originally misadionaigatemiedh in military research and development during World War II.Later,GEE was adopted instead of the descriptive AN system gy (MIT)Radiation Laboratory and were used 28 IEEE microwave magazine March/April 2014
28 March/April 2014 and ranging. The range of the object is obtained by measuring the time difference between the return signal and transmitted signal, while the velocity of the object is determined by the difference between the received frequency and the transmitted frequency of the signal (Doppler frequency shift) [12]. Figure 4 shows a large radar antenna used to track space objects as well as ballistic missiles. Radar, in addition to its military applications, has found use in civilian applications such as airport air traffic control, weather mapping, automobile collision avoidance, speed guns, police detectors, Doppler sensors for occupancy monitoring [13], experimental demonstration of noncontact pulse-wave velocity monitoring using multiple Doppler sensors [14], as well as numerous other applications. Transistor Invention In 1947, the transistor was invented by scientists John Bardeen, Walter Brattain, and William Shockley (Figure 5) who later shared the Nobel Prize [15]. The transistor replaced vacuum tubes, serving as the foundation for the development of modern electronics and making possible the marriage of computers and communications. LORAN Navigation System Long-range navigation (LORAN) [16], [17] is a terrestrial radio navigation system that enables ships and aircraft to determine their position and speed from low-frequency (LF) radio signals transmitted by fixed land-based radio beacons using a receiver unit. LORAN was an American development, advancing the technology of the British Generalized Estimating Equation (GEE) radio navigation system that was used early in World War II. It originally was known as Loomis radio navigation (LRN) after Alfred Lee Loomis, who invented the longer-range system and played a crucial role in military research and development during World War II. Later, GEE was adopted instead of the more descriptive term. LORAN systems were built during World War II after development at the Massachusetts Institute of Technology (MIT) Radiation Laboratory and were used Figure 4. A long-range radar antenna, used to track space objects and ballistic missiles. (Source: Wikimedia Commons.) Figure 5. Photo of (from left) John Bardeen, William Shockley, and Walter Brattain, the inventors of the transistor. (Source: Wikimedia Commons.) Figure 6. A LORAN-C receiver for use on merchant ships. (Source: Wikimedia Commons: Morn the Gorn.) The GPS project was developed in 1973 [45] to overcome the limitations of previous navigation systems
Extensively by the US.Navy and th BNayy.The AM radio began with the first N on raid CEE experimental broadcast in 1906 by The most recent version of LORAN is LORAN-C Reginald Fessenden and was used [18],which operates in the LF portion of the radio spec for small-scale voice and music trum from90 to 110 kHz(Figure 6).Many nations have broadcasts up until World War I. identic n in the s chayka"(Russian for "seagull).In recent decades C=WIog:(1+) LORAN use has been in steep decline,with the sat ellite-based global positioning system (GPS)being the primary repla ove Automobile Mobile Telephone Service In the United States,engineers from Bell Labs begar omplicated coding scheme.For R<C,it is not pos work on a system to allow mobile users to place and sible.This important relationship provided a limit to from automo lea maximum capacity of a chann in terms of the sig- naugua ommunication ontributions of Shannon's 201 include. ogy,which allowed reuse of freque ncies many times in .Shannon-Eano coding Nyquist-Shannon sampling theorem smitters,mad oding theorem Information Theory channel capa Claude Elwood Shannon (1916-2001)(Figure 7)was an American mathematician electronic engineer n as ather inform detection and correction(channel encod g).However, he founding both tor's de student at MID wrote his thesis demonstrating that electrical applica tions of boolean algebra could construct and resolve any logical,nume ship.A ve rsion of the I t in 1940.it eamed Shannon the Alfred Noble Amer Institute of American Engineers Award.It has been claimed that this was the most important master thesis of al me ]Sha tribute to the f his ba secure telecommunications Shannon provided major contributions to modern communication theory.Shannon showed [22]that the system capacity.C. of a chanr av al s the au N.and the bandwidth.W.This Shannon-Hartley theory is stated as USA Inc.) March/April 2014 IEEE mcrowave magazine 29
March/April 2014 29 extensively by the U.S. Navy and the Royal Navy. The British Royal Air Force also used LORAN on raids beyond the range of GEE. The most recent version of LORAN is LORAN-C [18], which operates in the LF portion of the radio spectrum from 90 to 110 kHz (Figure 6). Many nations have used the system, including the United States, Japan, and several European countries. Russia uses a nearly identical system in the same frequency range, called “chayka” (Russian for “seagull”). In recent decades, LORAN use has been in steep decline, with the satellite-based global positioning system (GPS) being the primary replacement. Automobile Mobile Telephone Service In the United States, engineers from Bell Labs began work on a system to allow mobile users to place and receive telephone calls from automobiles, leading to the inauguration of mobile service on 17 June 1946, in St. Louis, Missouri [19]. Shortly after, AT&T offered mobile telephone service. The introduction of cellular technology, which allowed reuse of frequencies many times in small adjacent areas covered by relatively low-powered transmitters, made widespread adoption of mobile telephones economically feasible. Information Theory Claude Elwood Shannon (1916–2001) (Figure 7) was an American mathematician, electronic engineer, and cryptographer known as “the father of information theory” [20], [21]. Shannon is famous for having founded information theory with a landmark paper that he published in 1948 [22]. This paper contains the basis for data compression (source encoding) and error detection and correction (channel encoding). However, he is also credited with founding both digital computer and digital circuit design theory in 1937, when, as a 21-year-old master’s degree student at MIT, he wrote his thesis demonstrating that electrical applications of boolean algebra could construct and resolve any logical, numerical relationship. A version of the paper was published in the 1938 issue of Transactions of the American Institute of Electrical Engineers [23] and in 1940, it earned Shannon the Alfred Noble American Institute of American Engineers Award. It has been claimed that this was the most important master’s thesis of all time [24]. Shannon contributed to the field of cryptanalysis for national defense during World War II, including his basic work on code breaking and secure telecommunications. Shannon provided major contributions to modern communication theory. Shannon showed [22] that the system capacity, C, of a channel perturbed by additive white Gaussian noise (AWGN) is a function of the average received signal, S, the average noise power, N, and the bandwidth, W. This Shannon–Hartley theory is stated as C Wlog N S = + 2 c m 1 , where W is in hertz, and the capacity is in bits/s. It is theoretically possible to transmit information over such a channel at any rate, R, where R C $ , with any arbitrary small error probability by using a sufficiently complicated coding scheme. For R C 1 , it is not possible. This important relationship provided a limit to the maximum capacity of a channel in terms of the signal to noise. Other communication contributions of Shannon’s [20] include: • Shannon–Fano coding • Nyquist–Shannon sampling theorem • noisy channel coding theorem • rate distortion theory • information theory • channel capacity Figure 7. Claude Elwood Shannon,“the father of information theory.” (Photo Reprinted with permission of Alcatel-Lucent USA Inc.) AM radio began with the first experimental broadcast in 1906 by Reginald Fessenden and was used for small-scale voice and music broadcasts up until World War I
Radar can be traced back to the work Television Development of Heinrich Hertz in the late 19th In the 1930s,analog television (TV)broadcasting century that showed that radio waves began 251.in 953,t were reflected by metallic objects. in the United States 261.In 196 or h was standardized on the phase alternating line(PAL format in Europe [271.with broadcasts starting in 1967 .confusion and diffusion .shannon's、 e coding theorem High-definition TV (HDTV)ec ·information entropy duced in the United States in the 1990s by the Digita 。Shannon's expansion HDTV Grand Alliance,a group of television,elec compan MIT The July1996[28 The first regular HDTV bro ion had ben active since the International Broadcastin Convention (IBC)exhibition in September 2003,but the New Year's Day broadcast marke d the official launch official start of direct-to Radio Development In 1954,Regency introduced a pocket transistor radio the TR-1 [30 powered by a standard 225-V battery.In 31.sony ir nrst tra d at there were no tubes to burn out over the next 20 vears transistors displaced tubes almost completely,except for very high-power or very high frequency use with the signal br nationwide.across a much wider aphical area than terrestrial radio stations.while transmitting higher-quality sound 3233).It is available by sub cription,mostyc ee,and options than te iety of programming in 1994 the us Army and Defense Advanced Research Projects Agency (DARPA)launched an ssful project to construct a software io on the fly by Radio Communication Satellite Systems In 1963,the first(radio)communication satellite,Tel star,was launched first tw nearly 5 on 10 July 1962.It successfully relaved through spac 30 IEEE microwave magazine March/April 2014
30 March/April 2014 • confusion and diffusion • Shannon number • Shannon index • Shannon’s source coding theorem • information entropy • Shannon’s expansion. Television Development In the 1930s, analog television (TV) broadcasting began [25]. In 1953, the National Television System Committee (NTSC) color TV system was introduced in the United States [26]. In 1960, color broadcasting was standardized on the phase alternating line (PAL) format in Europe [27], with broadcasts starting in 1967. By this point, many of the technical problems in the early sets had been worked out, and the spread of color sets in Europe was fairly rapid. High-definition TV (HDTV) technology was introduced in the United States in the 1990s by the Digital HDTV Grand Alliance, a group of television, electronic equipment, communications companies consisting of AT&T Bell Labs, General Instrument, Philips, Sarnoff, Thomson, Zenith, and MIT. The first public HDTV broadcast in the United States occurred on 23 July 1996 [28]. The first regular HDTV broadcasts in Europe started on 1 January 2004, when the Belgian company Euro1080 launched the HD1 channel with the traditional Vienna New Year’s concert. Test transmissions had been active since the International Broadcasting Convention (IBC) exhibition in September 2003, but the New Year’s Day broadcast marked the official launch of the HD1 channel and the official start of direct-tohome HDTV in Europe [29]. Radio Development In 1954, Regency introduced a pocket transistor radio, the TR-1 [30], powered by a standard 22.5-V battery. In 1960, Sony introduced their first transistorized radio [31], small enough to fit in a vest pocket and able to be powered by a small battery. It was durable because there were no tubes to burn out. Over the next 20 years, transistors displaced tubes almost completely, except for very high-power or very high frequency uses. Satellite radio is a radio service broadcast from satellites primarily to cars, with the signal broadcast nationwide, across a much wider geographical area than terrestrial radio stations, while transmitting higher-quality sound [32], [33]. It is available by subscription, mostly commercial free, and offers subscribers more stations and a wider variety of programming options than terrestrial radio [34]. In 1994, the U.S. Army and Defense Advanced Research Projects Agency (DARPA) launched an aggressive successful project to construct a software radio that could become a different radio on the fly by changing software [35]. Radio Communication Satellite Systems In 1963, the first (radio) communication satellite, Telstar, was launched. The first two Telstar satellites were experimental and nearly identical. Telstar 1 (Figure 8) was launched on top of a Thor-Delta rocket on 10 July 1962. It successfully relayed through space Figure 9. Engineers (from left) Stanley R. Peterson and Ray Bowerman check out the Early Bird—the world’s first communication satellite. (Source: Wikimedia Commons.) Figure 8. The original Telstar had a roughly spherical shape. (Source: Wikimedia Commons.) Radar can be traced back to the work of Heinrich Hertz in the late 19th century that showed that radio waves were reflected by metallic objects