5G Cellular and New Radio

Satisying growing traffic demands

1000Mbps for all subscribers in a cell
- Cell radius ~500m to 2Km
- Density of users : city centre -0.1 to 0.1 humans/m²
The traffic growth is so huge
Performance metrics
- Shannon Channel capacity
  - $C=Blog_2(1+S)$
  - B is the bandwidth
  - S is the SINR(signal-to-interference plus noise ratio)
    - $S=\frac{P_R}{BN+I} $
    - $P_R$ is the signal power at the receiver
    - $N$ is the thermal noise, constant
    - I is the aggregated interference
- Signal power at the receiver
  - $P_r = P_TAd^{-Y}$
  - $P_T$ is the emitter power at the transmier
  - A is the constant that depends on antennas/frequency
  - Y is the “path loss exponent” deponds on environment
FINAL VERISON = $C=Blog_2{(1+\frac{P_R}{BN+I})}$
- PHY Layer mechanisms
  - FEC,MIMO,ARQ, 90% to shannon
- Increse emitted power
  - may increase interference
- Decrease thermal noise
  - Constant up to 0.6Thz
  - may use superconductor
- Decrease interference
  - Logarithmic increase of C
- Increase bandwidth
  - Almost linear increase of C
- Network Mechanisms
  - Better Spatial frequency reuse

buy more licenced frequencies
- Commercial netwoks(cellular networks)
- Exclusive access
- Ablity to use higher transmission power >1mW
- High costs and risks
- Less than 100-500Mhz overall in a country(less than 3Ghz )
Use the unlicensed spectrum
- ISM bands (Industrial, scientific, medical bands)
- Extreme interference from Wi-Fi-s
Spectral Efficiency
- the information rate that can be transmitted over a given bandwidth in a specific communication system
Quadrature Amplitude Modulation
- PSK+ASK :S(t)= $Acos(wt+\phi)$, modulating $w $and $\phi$
Higher frequency then more bandwidth available
5G: millimeter wave (mmWave)
- 28Ghz
- 60Ghz(802.11ad)
- 72Ghz
- Postives
  - Highly directional antennas
- Negative
- Blockage by humans
- Large propagation losses
- Realistically up to 100m
B5G,6G: teraherz(sub-mmWave)
- 275-325 GHz: 50Ghz of bandwidth
- IEEE 802.15 3d”100Gbps wireless”
- Positive
  - Even more directivity
  - Hugh channel capacity
- Negative
  - Atmospheric absorption（大氣吸收）
  - Blockage by Human
  - Extreme propagation losses
- up to 10-20m realstically
  5G and New Radio Interface

Resembles properties of CPS
- CPS is Technological systems where physical and cyber components are tightly integrated(smartphone)
Moves us closer to tactile Internet（觸覺互聯網） conecpt， next IoT
Has to be supoorted by 5G/5G+ mobile cellular systems
At least two of the following are required
- High throughput
- High reliability
- Low latency
Reliable service over inherently unreliable medium

Enhanced mobile broadband(eMBB)
- data-driven use cases requiring high data rates across a wide coverage area.
Massive machine-type communications(mMTC)
- NB-IoT technology
Ultra-reliable low-latency services (URLLC)
- Not yet available and no dates annouced

Very small wavelengths
- 30Ghz ~1mm
  - Cannot penetrate through objects
  - Cannot travel around
Blockage happens at sub-second scales
- Models for various environments needed

Massive MIMO to form directional radiation patterns
- Linear arrays HPBW～102/N
Positive effects
- Much less interference
- Noise-limited regime?
Negative effects
- Beam alignment needed
- Array swtiching time ~2us
- Exhaustive vs hierarchical
- Delay and loss in capacity ？

Main chanllenge
- NR frame duration : 1ms
- Latency <1ms
- How to conform?
Two principle ways
- Reservation/priorities
- Non-Orthogonal multiple access (NOMA)
  - International overlapping of data
  - Enable by flexible NR slot numberology

Bloackage may or may not lead to outage(中斷)
- Case 1: blockage leads to lower MSC scheme - MSC: Mobile Switching Service Centre
  - Case 2: bloackage leads to outage
Solution
- Case 1: provide more resources
  - Bandwidth reservation
  - Isolated deployments
- Case 2: find a new path
  - 3GPP multi-connectivity
  - Dense deployments