Before studying the objectives of 4G, let us understand some of the characteristics of 4G, which are summarized here in table 1.
Achievable Data Rates | 10 Mbps (wide coverage) to 1 Gbps (local area). These are design targets and represent cell overall throughput. |
Networking | All-IP network (access and core networks). Plug & Access network architecture. An equal opportunity network of networks. |
Ubiquitous | Mobile, seamless communications. |
Cost Reduction | Cost per bit: 1/10-1/100 lower than 3G Infrastructure cost-1/10 lower than 3G. |
Connected Abilities | Person to person communication Person to Machine communication/Machine to machine communication. |
The objective of 4G is to cater the quality of service and rate requirements set by the forthcoming applications like wireless broadband access, Multimedia Messaging Service, video chat, mobile TV, High definition TV content, DVB and minimal service like voice and data at anytime and anywhere 4G is being developed, the 4G working groups have defined the following as the objectives of the 4G wireless communication standard.
- Spectrally efficient system (in bits/s/Hz and bit/s/Hz/site)
- Nominal data rate of 100 Mbps at high speeds and 1 Gbps at stationary conditions as defined by the ITU-R
- Data rate of at least 100 Mbps between any two points in the world
- Smooth handoff across heterogeneous network
- Seamless connectivity and global roaming across multiple networks i.e. seamless services with fixed NW (Net Work) and private
- High quality of service for next generation multimedia support (real time audio, high speed data, High-Definition Television (HDTV) video content, mobile TV, etc)
- Higher frequencies: Microwave: 3-10 GHz
- Interoperable with the existing wireless standards
- All IP system, packet switched network
- Next-generation Internet support: IPV6, QoS, MoIP (Mobile over IP)
- Lower system costs: 1/10 of IMT-2000
In summary, the 4G system should dynamically share and utilize the network resource to meet the minimal requirements of all the 4G enabled users. Figure 1 illustrates here a prospective view of physical layer of 4G.
Figure 1: Prospective physical layer of 4G
Key Parameters
The move to 4G is complicated by attempts to standardize on a single 3G protocol. Without a single standard on which to built, designers face significant additional challenges.
Table 2 compares some of the key parameters of 3G and 4G. Though 4G does not have any solid specification as of yet, it is clear that some standardization is in order.
Key Parameters | 3G | 4G |
---|---|---|
Frequency Band | 1.8-2.5 GHz | 2-8 Ghz |
Bandwidth | 5-20 MHz | 5-20 MHz |
Data Rate | Upto 2 Mbps | Upto 20 Mbps |
Access | W-CDMA | MC-CDMA or OFDM (TDMA) |
Forward Error Correction | Convolutional Rate | Concatenated coding scheme |
Switching | Circuit/Packet | Packet |
Mobile Top Speeds | 200 km/h | 200 km/h |
Component Design | Optimized antenna design, multi-band adapters | Smarter Antennas, software multiband and wideband radios |
IP | A number of air link protocols, including IP 5.0 | All IP (IP6.0) |
4G Network Requirement
From above it is clear that 4G is immensely complicated and hence there will be special requirement for future networks. Some of these tentative requirements are hereby summarized in table 3.
Media | Transmission speed | Delay | Connection Latency | Terminal capabilities |
---|---|---|---|---|
Speech/3D Audio | < 1 Mbps | < 50ms | < 1 sec | 3D sound field control High efficiency loud speakers |
Video/3D video | 10 Mbps (2D video) - 30 Gbps (3D video) | < 50ms | < 1 sec | Real time hologram |
Enhanced Reality | < 1 Mbps | ≪ 50 ms Should be predictable | N/A | Eyeglass display 3D and multimodal UI |
Five senses communications | < 1 Mbps | < 50ms | N/A | Five sense sensors |
Tele-existence | < 10Mbps (Robotic I/F) < 1 Gbps (Virtual avatar) < 100 Mbps (Alter-ego existence) | < 10 ms < 30ms < 5 ms (Small and known jitter) | 1 Sec | Alter-ego robot |
Development of 4G
There are many phases of developing 4G mobile communication systems. Let us study here two phases, i.e. development period and maturity period, which are described in table 4.
4G Mobile Communications | ||
---|---|---|
Phase 1 (2009-2010): Developmental Period | Phase 2 (2011): Maturity Period | |
Core cellular systems | 3.5G 3.5G mobile-communications system enhancing IMT-2000 (HSDPA/1xEV-DV) | 4G 4G Mobile-communications systems |
Transmission speed | 30 Mbps | 50 Mbps-100 Mbps |
Service level | High-level application service | Service with higher-level authentication and security |
Main users | Advanced users | General users |
Functions | Basic functions | Fully-fledged system |
Seam-lessness with other systems | Flexible realization of seamlessness with other systems | Seamlessness with no awareness thereof |
Social impact | Positioning with social functions | Positioning as a factor inducing changes in social structure. |
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