 Hello, welcome to another module in wireless communications in this MOOC, massive open online course. And this concluding module, we are going to look at some of the road map for the future in wireless communication system. We are going to look at some of the state of the art wireless communication technologies and what is upcoming in these wireless communication technologies. Let's start by looking the dominant wireless communication technology that is the 4G standard LTE, which is Long Term Evolution. This again developed by the 3GPP that is the third generation partnership project, which is the same umbrella body that overlooks the development of WCDMA. And LTE in a sense is an evolution of WCDMA and LTE is aimed at meeting basically by enabling broadband data rates over wireless networks and this is to enable vast array of applications such as online gaming, mobile TV, high definition mobile TV, broadband content streaming such as broadband movie streaming, broadband video calling etc. And LTE again is tied to the development of the other 3GPP standards as WCDMA, where in the early 2000s different standards or different releases in WCDMA were developed followed by the preliminary version of LTE in 2008 and with early deployments of LTE in 2010. And this is again something that we have already seen, which was a systematic evolution of the data rate from around 400 kilobits per second in the first release of WCDMA to about 14 megabits per second, 28 megabits per second in HSDPA and HSPA plus releases followed by LTE, which is a true broadband standard which can enable data rates about 160 megabits per second in the downlink and 50 megabits per second in the uplink. LTE again similar to YMAX is based on the powerful OFDM radio signal transmission technology that is orthogonal frequency division multiplexing and it is built for high speed broadband wireless access. It has a very high spectral efficiency that is in the same bandwidth on the same spectrum can support at a very, support a very high data rate by transmitting a large number of information bits for every symbol that is up to 6 bits per symbol, transmits data rates of about 200 to 300 megabits per second in the downlink and about 50 to 100 megabits per second in the uplink and also supports both time division to multiplexing and frequency division to multiplexing mechanisms. And it supports a huge bandwidth of about 20 megabits and as we already seen larger bandwidths implies higher data rate and also supports advanced antenna techniques where you have multiple antennas with to improve the diversity. Also MIMO that is multiple antennas at the transmitter and receiver to achieve a very high data rate and all the interfaces and backhaul are based on the internet protocol or an IP kind of a network to enable seamless connection to the internet to enable the rich set of services that the internet has to offer. And also has a high quality of service reliability. It ensures not just services such as video, video calling, video streaming but also has a strict set of guidelines to meet the quality of each service and therefore that makes the experience of that is intended to make the experience of each of the users a much more pleasurable experience, a much more convenient experience rather than experiencing for instance jitter in video or stalling of video etc. So it has higher grade of quality of service or higher quality of service reliability and also enables roaming backward compatibility with other 2G and 3G wireless networks where 4G is not readily available. The other wireless standard not wireless cellular standard but the other popular wireless data transmission mechanism is the wireless LAN or Wi-Fi which has become equally popular in the past decade. Wireless LAN stands for wireless local area network. It is the wireless component of a wired local area network such as Ethernet which supports high data rates going up to currently around the gigabit per second in a local area network and that provides a flexibility and mobility for indoor equipment rather than being tethered on Ethernet to provide a flexibility to connect various devices in a local area network. For instance here you have a basic schematic of a Wi-Fi architecture where you have the internet connected to a server and various access points to which the various Wi-Fi devices are connected such as laptops, smartphones etc. And the other advantage of Wi-Fi is it operates in the unlicensed bands such as the ISM which is the industrial scientific medical band and the UNII band, the unlicensed national information infrastructure band and this allows for fast deployment and development by multiple operators and vendors making the Wi-Fi ecosystem a very rich one rather than restricted to a few carriers and develop a vast set of applications or employed for a vast set of purposes such as not just commercial purposes but for educational and medical purposes. And the Wi-Fi or the wireless LAN have the advantage that they can provide connectivity in hotspot areas such as homes, offices, coffee shops, airports, hubs, university schools, educational institutes, offices, government institutes, community centres etc. Enabling the connection of a rich set of devices and internet and data access for a rich set of devices. And the wireless LAN standard is predominate dominated by the 80.11x based services also known as Wi-Fi, Wi-Fi is the colloquial term or the used or the trade term used for the 80.11x or 80.11suit of services developed by IEEE. And the various IEEE standard, 80.11 standards are such as 80.11a the more popular 80.11b which was formulated in 1999 and can support up to 11 megabits per second. And the latest one such as 80.11g and the more recent one such as 80.11n which can support up to about 150 megabits per second is based on OFDM and 80.11ac which is the most recent one can support up to a gigabit per second and is again based on OFDM. And the advantages of Wi-Fi or Wi-W LAN is that it supports mobility which leads to higher efficiency, cost effective ownership and cost effective installation compared to installation of a wired infrastructure such as Ethernet and enables dynamic reconfiguration of the entire network. And as you are all most of you must be familiar WLAN the connection to WLAN is to WLAN adapter. Most of these WLAN adapters now come standard with either laptops or smartphones that enable ready connection to Wi-Fi network whenever one is available. And the WLAN typically connects consists of access points which are equivalents of LAN hubs and these access points communicate with the WLAN adapters through antennas on the devices such as on your smartphones or on your laptops. And the wireless the WLAN access point typically has a range of about 20 to 500 meters so therefore it is much shorter range than a cellular network which is range of several kilometers supports about 15 to 100 users and therefore if you have a large hotspot with a large number of users you need a large number of access points to cover provide service to a large number of users. The other interesting wireless standard which is also very popular is Bluetooth which is formally known as WPAN or a wireless personal area network and the technical number for Bluetooth is IEEE 82.15.1. Bluetooth is primarily intended as a cable replacement technology that is for instance let us say you have a headset or a pair of headphones and you want to connect it to your smartphone or laptop instead of having a cable and instead of having a large these large number of devices having a large number of cables one can conveniently use Bluetooth to connect in this low range the small devices rather than using cables one can use Bluetooth and connect a variety of devices such as PDAs, printers, cell phones, storage devices, setup boxes etc. For instance here you have a typical Bluetooth ecosystem which has a laptop along with a tablet, PDA, printer, a mouse, another laptop, mobile phone, headset and various such devices and the range of Bluetooth is typically small it is about 0 to 10 meters much smaller of course even than Wi-Fi and rates are also around 20 to 100 kilobits per second which is suitable for connecting headsets connecting printers etc. And typical Bluetooth devices cost supposed to be inexpensive at about 10 to 100 dollars and also the transmit power is supposed to be low so that they cause minimum interference to other Bluetooth devices making a large number of making it possible to support a large number of Bluetooth devices in a given area. There are other future wireless technologies such as LTE Advanced which is an advanced version of LTE which is supposed to support bandwidths of several about 100 MHz and support data rates of about up to a gigabit per second if not more and another interesting future wireless technology is cognitive radio which is very interesting with and is based on what is known as dynamic spectrum allocation currently most devices wireless communications are based on static spectrum allocation that is a certain portion of the spectrum is allocated to the device for a fixed amount of duration rather than make that spectrum allocation static the spectrum can be dynamically allocated or shared by several users or secondary users and that is the foundation for the cognitive radio paradigm and this is a very promising wireless paradigm which is expected to be developed and implemented in the near future and it is based on a key aspect technology aspect known as software defined radio which is basically based on a large number of different radio technologies which can be implemented in rather cheap software and can be deployed at relatively conveniently or various such radio technologies can be deployed in quick succession relatively conveniently over the same device thus making it possible to dynamically allocate different spectral regions to different devices. So these are the so this module as exposed this module basically looks as some of the other wireless technologies such as WLAN, Bluetooth and also some of the interesting upcoming wireless technologies. So that concludes the wireless communication module in this MOOC. Thank you. Thank you very much.