3/11/2025

5G

The ambition of 5G:

• lots of data speeds
• support lots of devices that have long battery life and are cheap
• quick latency and high reliability,

8 essential 5G technologies:

• massive MIMO
  • multiple input and output. the same spectrum can send more information. Huge number of transmitter, gets more capacity.
  • channel limit: limit on how much data you can send on one channel. like how u can't travel faster than the speed of light. So to get around this you make multiple channels. this was what LTe used.
  • exploits spatial dimension
    • beam is steered toward desired user and blanks out other. this is done with a large number of antennas relative to the number of users served. large number of radio frequency chains for dynamic beam shaping.
• mmWave:
  • mm wavelength cannot go through walls. If there's rain, it won't do well. 5G uses a lower wavelength that is up all the time, but then when its available, then you send a lot at once.
• multi-service air-interface design: wave form, frame structure
  • low latency packet retransmission
  • subframes that can be allocated to different users
• wireless front, mid, back-haul solution: coverage and capacity expansion at low cost
• low-latency air interface, edge computing, and end-to-end SDN
  • put a server right near a base station.
• spatial diversity, enhanced coding for ultra reliability
  • redundancy

Network Function Virtualization (NFV)

Why NFV?

• virtualization: use network resources without worrying about where it is physically located
• orchestration: how do you manage thousands of devices
• programmable: change behavior on the fly
• dynamic scaling: change size and quantity
• automation: let machines / software do human work
• visibility: monitor resources, connectivity
• performance: optimize network device utilization
• multi-tenancy: network for diff customers (as a service)
• service integration: let network management play nice with OSS/BSS
• openness: full choice of modular plug ins

NFV concept: makes hardware more flexible and simpler by minimizing dependence on hardware constraints:

• traditional: DPI BRAS, PE router, firewall, NAT all different hardware pieces. One physical node per role
• in virtualized network model: you have a few standard high volume servers, and you have virtual appliances that does each of these roles. Multiple roles over the same HW.

benefits:

• reduced equipment cost (CAPEX): economies of scale and consolidating equipment
• increased speed of time to market: minimizing network operator cycle of innovation
• availability of network appliance multi-version and multi-tenancy.
  • allows a single platform for different applications
• enables variety of eco-system and encourages openness
• encourage innovation to bring new services and generate new revenue stream
• flexibility to easily rapidly, dynamically provision new services
• operational efficiency
  • higher uniformity of physical platform
• software oriented innovation

ETSI NFV architectural framework

• etsi standards body
• lower level is the hardware resources (computing, storage, network) which is virtualized

service chain is a generalization of a pipe. complex.

NFV concept:

• network function (NF): functional building block with well defined interfaces and well defined functional behaviors
• virtualized network function (VNF) software implementation of NF that can be deployed in virtualized infrastructure
• vnf set: connectivity between VNFs not specified
• vnf forwarding graph: service chain when network connectivity order is important e.g., firewall
• vnf infrastructure: hardware and sfotware required to deploy, manage and execute VNFs, including computation, networking and storage
• nfv orchestrator: automates the deployment and operation of VNFs