It may support one or more cells, although, in general, only one cell one Node B. It is a logical terminal and the base station is often used for physical entity. Functions ◦ Mapping of Node B logical resources onto hardware resources ◦ Uplink power control ◦ Reporting of uplink interference measurements and downlink power information ◦ Contains the air interface physical layer, it has to perform many functions such as RF processing, modulation, coding, and so on.
23 BTS Node B BSC A bis BTS BSS MSC Node B Node B RNC I ub Node B RNS Node B SGSN GGSN GMSC HLR VLR I u PS I u CS I u CN EIR G n G i PSTN AuC GR PDN
24 The Core Network (CN) and the Interface I u are separated into two logical domains: Circuit Switched Domain (CSD) ◦ Circuit switched service including signaling ◦ Resource reservation at connection setup ◦ 3G versions of GSM components (MSC, GMSC, VLR, HLR) ◦ I u CS Packet Switched Domain (PSD) ◦ Handles all packet data services ◦ 3G versions of GPRS components (SGSN, GGSN) ◦ I u PS General approach of building on GSM/GPRS infrastructure, helps to save $ and faster deployment
25 HLR (Home Location Register) ◦ Database located in the user’s home system that stores the master copy of the user’s service profile. ◦ The HLR also stores the UE location on the level of MSC and SGSN, 3G MSC/VLR ◦ Switch and database that serves the UE in its current location for Circuit Switched (CS) services. ◦ The MSC function is used to switch the CS transactions, and VLR function holds a copy of the visiting user’s service profile, as well as more precise information on the UE’s location within the serving system.
26 3G GMSC (Gateway MSC) ◦ Switch at the point where UMTS is connected to external CS networks. ◦ All incoming and outgoing CS connections go through GMSC. 3G SGSN (Serving GPRS Support Node) ◦ Similar to that of MSC/VLR but is used for Packet ◦ Switched (PS) services. ◦ The part of the network that is accessed via the SGSN is often referred to as the PS domain. ◦ Upgrade version of serving GPRS support node. 3G GGSN (Gateway GPRS Support Node) ◦ Functionality is close to that of GMSC but is in the relation to PS services. ◦ Upgraded version of gateway GPRS support Node
27 There are four types of QoS classes ◦ Conversational real-time class such as voice traffic ◦ Interactive class (best-effort) such as web browsing ◦ Streaming real-time class such as streaming video ◦ Background class (best-effort) such as emails.
28 Traffic class Conversational Streaming Interactive Background Characteristics Preserve time relation (variation) between information entities of the stream Conversational pattern (stringent and low delay) Asymmetric applications More tolerant to jitter than conversational class.
You've reached the end of your free preview.
Want to read all 32 pages?
- Winter '20
- Universal Mobile Telecommunications System, CDMA2000, RNC