INTERNET ACCES TECHNOLOGIES

In this class Vicente Casares talks about broadband access networks for Internet. If we have to classify all access networks we divide this in 2 types: wired access networks and wireless access networks. In the first type we found xDLS and FTTx. xDLS technology was made with metallic cables and has multiple types of applications like ISDN or Asymetric (ADSL). FTTx was made with Optibal fibers and we found 4 types of implementations: FTTN (Fiber-to-node), FTTC (Fiber to the curb), FTTB (Fiber to the building) and FTTH (Fiber to the home).

In wireless access networks we have more variety because we have Cellular networks (like GSM, 3G or LTE), WLANs, Satellites and Cordless.

He also said that the growth in fixed and mobile traffic will increase a lot in the next years. Cisco VNI predict that global mobile data traffic will double every year through 2014, increasing 39 times between 2009 and 2014.

GSM-> This wireless network allows mobility, provides total ubiquity an allow coverage areas close to 40 Kms. This technology uses TDMA with 124 carriers and a total bandwidth of 25 MHZ for uplink (890-915 MHz) and downlink (935-960 MHz). The E-GSM (extended GSM) cover a little bit more of bandwidth adding 9.8 MHz. GSM uses the frequency bands 1800 MHz (DCS 1800) and 1900 MHz (DCS 1900).  GSM was evolving as the same time the technology improves, adding commercial services like telephony and short messages and improvements in advanced data transmission services together with voice coding techniques.

GPRS->Appear because of necessity of increase the number of data services offered by GSM. The objective of this technology was reach rates around 170 Kbps, use, if needed, the dynamic slot allocation and enhance the service facilities assuming moderated costs without big investments in the GSM infrastructure. This technology combines FDMA and TDMA and offers two classes of services: point-to-point (conexion oriented and less-oriented) and point-to-multipoint (multicast and group-services). This technology has two new nodes:  GGSN (is as logical interface with external data packet networks) and SGSN (is in charge to deliver data packets to the mobile stations which are located within the service area).

UMTS->Appear because of the technical, network and service evolution. This technology uses 12 carriers in FDD for uplink and downlink and 5 carriers TDD and allows conversational (real time), streaming, interactive and background applications. The UMTS systems have been enhanced with HSPA. HSPA consists of two components, HSDPA (define a new transport channel that allows to assign all available resource to one or more users in an efficient manner) and HSUPA (dedicated to channels have been enhanced).

SAE->Service Architecture Evolution. 3GPP was working in the specifications of EPC (Evolved Packet Core).  EPC is a multi-access core network based on the Internet Protocol that enables operators to deploy and operate one common packet core network. It is defined around three important paradigms: Mobility, Policy management and Security.

LTE-> Long Term Evolution Is the evolution of UMTS (3G->4G).  This technology is designed to deliver significantly higher levels of capability and performance. It will co-exist with the WCDMA and HSPA networks and introduces a new radio interface technology based in OFDM. The LTE access is based on shared channel access providing peak data rates of 300 Mbps (Downlink) and 7 Mbps (Uplink). LTE (E-UTRAN) is only connected to the EPC and its protocols and user plane functions have been optimized for the transmission of traffic from IP based real-time and non-real-time applications/services.