Wireless technologies have has come a long way from its early days, evolving at an exponential speed. Our experts are constantly working on the most cutting edge wireless technologies. You can learn more about them in our technology expert directory.
One of the more rapidly evolving wireless technologies is mobile communication. It was only in the 1980’s that the first analog cellular phone networks (AMPS, in the US) was commerically deployed. Cellular phones slowly became commonly available then, starting with Motorola’s “brick” phone. In the 1990’s the second generation (2G) of mobile networks (GSM, CDMA). This ushered in the era of short message services (SMS). In the same decade, General Packet Raedio Service (GPRS) was the successfully commercialized to provide improved mobile data services based on the GSM standard (sending data at about 14 Kbps). Nokia’s candy bar and Motorola’s clamshell phones ruled the mobile phone industry in this era. Internet enabled phones debuted in 1999 with Wireless Application Protocol (WAP).
Mobile Technologies Changes & Improvements
In 2000’s, incremental improvements to GSM led to the introduction of EDGE (the Enhanced Data rates for GSM Evolution), also known as EGPRS (Enhanced GPRS), with speeds of up to 135 Kbps. However, this was not considered a generational advancement. Third generation (3G) mobile technologies were pioneered by CDMA2000 (standardized by TIA and 3GPP2) in the US and Wideband CDMA (WCDMA) in Europe (standardized in 3GPP). This transition signaled the end of the dominance of TDMA (Time-Division Multiple Access) as the favorite multi-access protocol for cellular systems (IS-136, GSM, EDGE) and ushered in the dominance of various CDMA (Code Division Multiple Access) protocols based on direct-sequence spread spectrum technology. The 3G systems handily addressed the call capacity definiciencies of the older generations but they lacked in data capabilities.
Fourth generation (4G) cellular networks were finally commercially deployed in 2010’s, mainly driven by the increased demand for high- data rate mobile data applications (which, in turn, was caused by the popularity of high-data-rate internet applications such as Youtube). LTE (Long Term Evolution) was standardized by 3GPP and eventually adopted by all countries as the de facto 4G cellular standard. Unlike the previous generations, LTE is based on the OFDMA (Orthogonal Frequency Division Multiple Access) multi-access technology, which offered higher spectral efficiency (higher data rates in the same RF spectrum). To achieve even higher data rates, LTE also incorporates MIMO (Multiple-Input Multiple-Output) techniques, a multi-stream communication scheme whereby each stream is sent from/to different antennas on the transmitter/receiver. For example a 2×2 MIMO support in LTE means that 2 antennas (and 2 RF chains) at the base station and 2 antennas (and 2 RF chains) at the mobile station can be utilitzed (along with a generous amount of digital signal processing on both ends) to tremendously increase the throughput of the communication link without increasing the RF bandwidth used. LTE can achieve up to 300 Mbps in downlink (DL) and 75 Mbps in uplinke (UL).
LTE standard is being followed by LTE-Advanced (LTE-A). Using techniques such as Carrier Aggregation, Coordinated Multipoint (CoMP), Relay Station, 8×8 MIMO, and Heterogeneous Network (HetNet), even greater data rates (3Gbps DL, 1.5 Gbps UL) are achieved. Spectral Effincieny, user capacity, and quality of service is also dramatically improved. However, LTE-A is not considered a new generation in the evolutionary path of the cellular networks.
Fifth Generation (5G) mobile technology standardization has just started in 3GPP in early 2015 and its completion is expected to be around 2020. As such, it will be a while before we see the standard, and even longer before it is commercially deployed. However, it is the hot topic in the industry, as it is considered to be one of the enabling wireless technologies for IoT (Internet of Things) responsible for smart cars, wearables and communicating devices.
Wireless local area networking (WLAN) has also seen dramatic changes over the years. It has evolved quite rapidly in the past two decades. First standardized in IEEE 802.11 in 1997 and commercially promoted by the Wi-Fi Alliance, it offered 2 Mbps data rates while utilizing 22 MHz of RF spectrum. Shortly thereafter, the 2nd generation improved the maximum data rate to 11 Mbps using spread spectrum techniques in 20 MHz of bandwidth (802.11b). The 2000’s witnessed the commercialization of the 3rd generation of Wi-Fi technology (802.11a in the 5 GHz band, and 802.11g in the 2.4 GHz band), improving data rates up to 54 Mbps using OFDM modulation techniques. 4th generation Wi-Fi was ushered in the long-awaited 802.11n standard amendment, which utilized 4×4 MIMO along with 40 MHz of RF bandkwidth to improve data rates up to 600 Mbps (150 Mbps per stream).
Currently, we are witnessing the successful commercialization of the 5th generation Wi-Fi products based on IEEE 802.11ac, which increased the max data rate to several Gbps. Multi-User MIMO (MU-MIMO) and RF bandwidths of up to 160 MHz have a lot to do with this improvement, while still utilitzing the traditional 2.4 GHz/5 GHz RF bands. The 802.11ad standard amendment, on the other hand, uses the 60 GHz RF spectrum (millimiter wave) to provide WiGig-branded products to the market using RF bandwidths of over 2 GHz. The max data rate of 802.11ad is about 7 Gbps.
As referenced above, IEEE 802.11 standard has evolved via various amendments to the original (1997) standard. However, at two points in time, the cumulative amendments were combined to create a new standard. The amendments made earlier than 2007 (a, b, d, e, g, h, i, and j) were all rolled up into the main 802.11 standard and renamed 802.11-2007. And, in 2012, new amendentments (k, n, p, r, s, u, v, w, y, z) were rolled again into what is now called 802.11-2012. The amendments since then are ac, ad, af, ah, ai, aj, aq, ax, ay.
Other wireless technologies have come a long way as well. For example, Bluetooth, initially considered as useless and left for dead, has evolved from its original version into a variety of flavors for different applications. Other wireless technologies (e.g., Zigbee) have survived the test of time as well. Others (e.g., WiMAX, WiMedia) did not fair well and were abandoned by the industry. Terrestrial and Satellite digital broadcasting standards (for TV and Radio) have evolved over the same years as well (DVB-T/S/H , ISDB-T/S/C/1seg, DAB, DRM,…)
As the surviving wireless technologies evolved, they started to compete with each other for applications as well as spectrum. For example, Bluetooth and Wi-Fi have long competed over spectrum, causing interference issues between their respective networks. Consequently, coexistence protocols have been devised to allow for cooperative management of interference. For example, manufacturers of Wi-Fi/Bluetooth combo modems commonly use coexistence standards to allow their product to be used in either networks as interference-free as possible. Interworking between 3G/4G cellular and Wi-Fi networks is also commonplace, allowing for throughput-limited cellular networks to piggy-back on available Wi-Fi networks to provide improved data rates at lower costs. More innovative, multi-dimensional approaches to seamless interworking protocols are being contemplated as we speak to allow for mobile devices to choose the best access technology available at any given point.
The world of wireless communication has grown by leaps and bounds since only a few decades ago, and with it, the complexity and diversity of the systems and networks being implemented have exploded. This has enabled a plathora of applications to flourish. In a single smartphone, these days, over a dozen different wirless communication air-interfaces implemented (GSM, CDMA2000, WCDMA, LTE, GPS, Glonass, 802.11a, 802.11g, 802.11n, 802.11ac, Bluetooth, NFC, …), each with a variety of RF spectra to operate in as the phone is transported to various parts of the world. It is hard to believe that this all became possible through innovations that took place within our lifetime.
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