LTE - Long Term Evolution
- Standard for high-speed wireless communication for mobile devices.
- Based on GSM/EDGE and UMTS/HSPA technology.
- Common standard for paired and unpaired spectrum.
- LTE-FDD and LTE-TDD - 2 modes, common standards, same ecosystem
- Standard is almost same for FDD and TDD.
- Enables common FDD/TDD products.
- LTE-FDD (Frequency Division Duplex)
- Uses paired frequencies to upload and download data.
- Can cover larger area - only applicable to coverage driven deployments.
- Fixed uplink/downlink on different frequencies.
- LTE-TDD (Time Division Duplex)
- Uses a single frequency, alternating through time to upload and download data.
- Can assign more downlink capacity - flexibility to assign more resources to meet asymmetric data usage.
- Flexible uplink/downlink ratio.
LTE Advanced
- Better, faster mobile broadband experience
- Carrier Aggregation
- Combines multiple LTE carriers for wider bandwidth, eg. fatter pipe
- Enable mobile operators to maximize use of spectrum assets
- Aggregation across more carriers
- Aggregation across diverse spectrum types
- Makes the best use of spectrum, eg. FDD/TDD, unlicensed/licensed spectrum.
- Advanced MIMO (Multiple Input, Multiple Output)
- Leverages more antennas to increase spectral efficiency.
- Using higher order modulation: 256-QAM
- Increases spectral efficiency for faster downlink throughput.
- Increase bits per transmission (symbol)
- Heterogenous Networks (HetNets)
- Small cells to efficiently increase capacity
- Reuse spectrum assets
- Repeating Shannon’s Law everywhere
- Provide localized capacity
- For better signal quality, especially indoors
- Use unlicensed spectrum
- Opportunistically while maintaining anchor in licensed spectrum
- LTE Solutions for enhancing HetNets
- Interference Management - capacity scales with small cells added
- Best use of all spectrum - unlicensed spectrum, shared licensed and higher bands
- 5GHz unlicensed spectrum
- ideal for small cells due to low mandated transmit power
- large amounts of spectrum available
- Self organizing networks - Plug and Play
- Dual connectivity
- Coordinated Multi-point
Spectrum Sharing
2 or more systems operate in the same band - improving overall spectrum usage efficiency
- Authorized Shared Access
- Licensed Shared Access
- dynamic use of a spectrum wherever and whenever it is unused by the incumbent spectrum user on a voluntary basis.
- sharing could be done if incumbent uses only a subset of its frequency band, does not use the spectrum continuously and/or uses the spectrum only in a geographically limited area.
Spectrum Sharing in unlicensed spectrum
- Spectrum is a scarce resource.
- Design spectrum sharing rules and protocols in a fair, efficient way compatible with incentives of individual systems.
- Resource allocation is efficient if it is not possible to improve performance of a given system without degrading performance of another system.
Terminology and abbreviations
- CRS: Cognitive Radio Sensing
- A cognitive radio is a radio that can be programmed and configured dynamically to use the best wireless channels in its vicinity to avoid user interference and congestion.
- This is a form of dynamic spectrum management.
- MNO: Mobile Network Operator