Module within BSC that is responsible for handling packet traffic
Signalling System No. 7 (SS7)
A set of telephony signalling protocols which are used to set up most of the world’s PSTN telephone
Serving GPRS Support Node (SGSN)
Responsible for the delivery of packet from and to the mobile stations within its geographical area
It tasks include packet routing and transfer, mobility management, logical link management, and authentication and charging function
Location Register of SSGN stores location information and users profiles used in the packet data of all GPRS users register within this SGSN
Gateway GPRS Support Node (GGSN)
Responsible for interworking between GPRS network and external packet switched networks such as the Internet
3rd Generation Partnership Project (3GPP)
A collaboration between groups of telecommunications associations, known as the Organisational Partners
Initial scope:
Make a globally applicable 3G mobile phone system specificiation based on evolved GSM specs
3GPP standards are structured as releases
Universal Mobile Telecommunications System (UMTS) (3G)
Extends GSM / GPRS networks and uses W-CDMA air-interface
A 3G mobile communications system that provides a range of low-cost broadband services
Preserves the global roaming capability of GSM / GPRS networks
Designed to deliver media (pictures, video communication), as well as voice and data to mobile wireless subscribers
Data Rates
144 kbps - Satellite and rural outdoor
384 kbps - Urban outdoor
2048 kbps (2 Mbps) - Indoor and low range outdoor
Bandwidth for digital Voice:
Up to 64 kbps
Frequency bands
Europe & Asia
Band I (W-CDMA 2100 MHz)
Band VIII (W-CDMA 900 MHz)
Integration of Voice & Data Traffic
Multimedia apps require both voice and data
Main feature of 3G phone is to handle both voice and data
Data-oriented systems, e.g. 802.11 need to handle voice due to Voice over IP (VoIP)
UMTS Network Architecture
UMTS Network Architecture
UMTS Terminal / User Equipment (UE)
New name for GSM network’s MS
Reflects the greater functionality of UE
Radio Network Subsystem (RNS)
The equivalent of GSM network’s BSS
Provides and manages air-interface for overall network
UMTS Base Station (BS)
a.k.a. Node B in the context of UMTS
UMTS Radio Network Controller (RNC)
Manages radio resource and mobility
Point where encryption / decryption is performed to prevent eavesdropping
Handles all radio resource control functions (including handoff)
Whereas in GSM, handoff process shared between MSC & BSC
High-Speed Packet Access (HSPA) (3.5G)
High-Speed Downlink Packet Access (HSDPA)
Allows UMTS networks to provide higher downlink data transfer rates on smartphones
Up to 14.4 Mbps download speed
Key Benefits
Higher data transfer rates
Lower latency
Good for time-sensitive apps
Good for database transactions (many packets sent back & forth)
Better modulation techniques
Re-transmission from BS
Scheduling done at BS
High-Speed Uplink Packet Access (HSUPA)
a.k.a. Enhanced Uplink (EUL)
Up to 5.76 Mbps uplink transfer rate
Evolved HSPA (HSPA+)
Wireless broadband standard defined in 3GPP Release 7
Uses MIMO tech and higher-order modulation (64-QAM)
Bandwidth:
Downlink - up to 56 Mbps
Uplink - up to 22 Mbps
Future bandwidth - up to 168 Mbps (Possible by using multiple carriers)
Long Term Evolution (LTE) (4G)
Bandwidth:
Downlink - up to 150 Mbps
How it works
Air-Interfaces
2 different types of air-interfaces (radio links)
1 for downlink (tower to device)
1 for uplink (device to tower)
Cell tower uses multiplexing scheme that requires a powerful transmitter
LTE devices do not have a powerful signal going back to cell tower to conserve battery life
Devices use different multiplexing scheme, not required a powerful transmitter
Multiplexing Technique
Orthogonal Frequency Division Multiplexing (OFDM)
OFDM signal comprises a max of 2048 different sub-carriers with a spacing of 15 kHz
Within the OFDM signal, depending on signal quality, there are 3 types of modulation available to choose from
QPSK
16-QAM
64-QAM
Multiple-Input & Multiple-Output Antenna (MIMO)
MIMO devices have multiple input and output antennas
MIMO devices have multiple connections to a single cell
Increases stability of connection
Reduces latency tremendously
Increases total throughput of connection
LTE-Advanced (4G+)
Bandwidth:
Downlink - up to 300 Mbps
Technology Used
MIMO
Combines multiple antennas on both the transmitter (4G tower) and receiver (smartphone)
2x2:2 MIMO = 2 antennas on transmitter and 2 on receiver, transmitting and receiving 2 independent data streams
More antennas results in faster potential speeds as data streams can travel more efficiently
Carrier Aggregation
Allows device to receive multiple different 4G signals at once
Signals do not have to be on the same frequency
i.e. Can receive both 1800 MHz and 800 MHz signal at the same time
Not possible with standard 4G
Up to 5 different signals can be combined at once
Each up to 20 MHz of bandwidth
Combined to create a data pipe of up to 100 MHz of bandwidth
Relay Node
Low power Base Stations that provide enhanced coverage and capacity at cell edges & hotspot areas. Can also be used to connect to remote areas without fibre connection
Increases performance in networks with a mix of large and small cells
5G
Aims
Higher capacity than 4G
Increased no. of mobile broadband users per unit area
Allow consumption of higher or unlimited data quantities in GB per month
Feasible for large portion of population to stream HD media when out of reach of WiFi hotspots
Improved support of machine-to-machine (M2M) communication (a.k.a. Internet of Things)
Lower costs
Lower battery consumption
Lower latency than 4G
Standards
No current standard for 5G
Next Generation Mobile Networks Alliance defines that a 5G standard should fulfil:
Data rates of 100 Mbps for metropolitan areas
1 Gbps simultaneously to many workers on the same office floor
Hundreds of thousands of simultaneous connections for massive wireless sensor network
