Testbed Verification of New Fronthaul Technology for 5G Systems

Abstract

The fronthaul for 5 th generation mobile systems (and beyond) has evolved with new splits for the radio access network functions defined, and the transport for these split interfaces having very different requirements. Testing of the transport for such split interfaces is reported, and it is shown that an Ethernet fronthaul transport network, which is capable of bringing efficiency gains through statistical multiplexing, can meet stringent latency and latency variation requirements, assuming buffering and playout of the radio waveforms and that timing/synchronization signals are prioritized. An aggregation technique for a 100 Gb/s Ethernet trunk which provides for such timing signals is demonstrated. Real-time monitoring of the Ethernet fronthaul for software-defined networking control and performance optimization is also shown.

Testbed Evaluation of Distributed Radio Timing Alignment Over Ethernet Fronthaul Networks

“…However, they do not rely on the backhaul or FH network in order to achieve the timing alignment. Meanwhile, most testbed-based FH studies such as [28]- [30] focus on metrics like FH latency and PDV, rather than the RF timing alignment among cooperative RRUs. To the best of our knowledge, there are no publications focusing on practical evaluations of eCPRI's or RoE's mechanisms for timing alignment of distributed transmissions.…”

Ethernet fronthaul transport of an upper-physical layer functional split using time-aware shaping

“…The selection of this functional split option depends on several factors such as reduction of fronthaul bit-rate, and support of radio techniques such as multiple-input multiple-output (MIMO), massive and distributed MIMO and Coordinated Multipoint (CoMP) [10]. Using a new functional split in conjunction with Ethernet transport in the fronthaul has many advantages in comparison to use other transport technologies such as point to point, microwave links and Fibre Wireless Networks (FIWI), such as allowing for statistical multiplexing gains, and network virtualization, monitoring, orchestration and Software Defined Networking (SDN) [3,11,12].…”

“…However, an Ethernet network may lead to a lack of synchronization [3,7,10], increased delay and delay variation due to contention [3,12], mapping inefficiency [15], and packet loss [16].…”