Skip to 0 minutes and 10 secondsThe first generation of cellular technology was rolled out in 1983 and was called AMPS. This was an analog technology that enabled voice calls only. Mobile phones were big, bulky and expensive. In the early nineties, the first digital technologies emerged. Mobile phones got smaller in size and the number of subscribers grew rapidly.
Skip to 0 minutes and 37 secondsIn 1995, GSM and CDMA made their first appearance, bringing with them new mobile devices and support for SMS, fax and data. GSM started out in Europe but very quickly was adopted in many countries globally. In 2000, the first commercial GPRS services were launched and the first GPRS-compatible handsets became available for sale. GPRS provided data throughputs of up to 60 Kbps, using a new IP-based network architecture. In 2003 EDGE was introduced, as an enhancement to GPRS, providing data throughput of up to 400 Kbps.
Skip to 1 minute and 29 secondsIn 2002 the first 3G UMTS networks were launched. This was the first time a voice and data session could be run simultaneously. 3G networks provided data throughput of 384 Kbps. This throughput was substantially increased in 2006, with the introduction of 3.5G HSPA network, reaching values of 42 Mbps. The first 4G LTE operations were deployed between 2008 and 2010. 4G LTE is a data-only network, offering throughput of 100 Mbps. Voice calls were supported on the 2G or 3G networks. Voice-over LTE or VoLTE has been available since 2014, providing voice services over the LTE data network, similar to Skype but with assured quality of service. LTE-Advanced is nowadays being deployed, providing data throughputs of 300 Mbps.
Skip to 2 minutes and 42 secondsThe 5G networks are expected around 2020 and will focus on providing data throughputs of 1 Gbps. A cellular network comprises of a Radio Access Network, or RAN, a transport network and a core network. The RAN part contains the base stations and antenna that we see all around us. It provides access for the users to the network. The core network contains voice switches and IP routers. It performs the connection of the user to the requested destination, like another user for a voice call or the internet for other services. The transport network connects the RAN to the core network, using fiber-optic cables or copper cables, microwave links or even satellite connectivity.
Skip to 3 minutes and 44 secondsLooking deeper into the RAN, we define two directions for communication between the base stations and the user devices. Downlink, this is the link from the base-station to the user equipment, for example, when we download files. Uplink, this is the link from the user equipment to the base-station, for example, when we upload pictures. The information exchanged between the base station
Skip to 4 minutes and 12 secondsand the user equipment is made up of: Control or signaling data, used for the setup of the session, for example, the dialed phone number, or the web address, and the content that is delivered or downloaded, be it voice or data.
Skip to 4 minutes and 32 secondsThere is a global agreement that defines which frequency bands are allocated to cellular communications. The most common bands are 800 MHz, 900 MHz, 1800 MHz, and 2100 MHz. Every regulator in each country allocates specified bandwidth in the cellular frequency bands to the different service providers in that country. The available frequency allocations are usually auctioned between the service providers, which make huge financial investments in acquiring them. The cellular frequency bands can be used for any technology (2G, 3G, and 4G). However, a regulator in a specific country may dictate the technology to be used in specific frequency bands, for example, 2100 MHz only for LTE, 1800 MHz for 3G and/or LTE.
Cellular Network Basics
This clip introduces you to some basic Radio Frequency (RF) terminology, which will be used throughout our course. It will also give a brief history of cellular technology from the first generation (1G) to 5G; and describe network components at a high level.