From: Realizing 5G vision through Cloud RAN: technologies, challenges, and trends
Transport technology | Advantages | Issues |
---|---|---|
Optical networks | High-capacity | Expensive optical devices |
 | Reduced fiber resources | Requires previous infrastructure |
 | Passive (in the case of passive optical networking) | Challenging network extensibility |
CPRI-over-Ethernet | Efficient | Packetization introduces overhead and latency |
 | Cost-effective | Ethernet is an asynchronous protocol, while fronthaul has strict synchronization requirements. |
 | Universal availability of interfaces |  |
Millimeter-wave frequencies | High scalability and capacity | High path loss |
 | High frequency reuse | Low penetration |
 | Small form factor | Line-of-sight requirement |
 | Underutilized spectrum |  |
 | Point-to-multipoint links |  |