Timing Over Packet - Nokia Flexi Zone Pico Product Description

Synchronization

7.3 Timing over Packet

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SyncE provides a high quality synchronization reference for base stations, comparable to
SDH synchronization. The stability of the recovered frequency is independent of the
network load or network impairments like delay variations.
A co-located or another chained tail site can be synchronized with Synchronous Ethernet
generation using SyncE.
Both BTS Synchronous Ethernet and Timing over Packet features can be activated
simultaneously. The features can be set individually as primary and secondary
synchronization sources. When both SyncE and IEEE1588 ToP are feasible in the
priority configuration, the selection of ToP or SyncE as primary or secondary references
is a key point in the design of the synchronization network and depends very much on
the characteristics of the mobile backhaul network being used to access the BTS.
In addition, when Synchronous Ethernet Generation feature is activated, both SyncE and
Timing over Packet can serve as an input for generating SyncE signal towards
chained/collocated BTS.
Timing over Packet (ToP) can be also considered as an example of master-slave
architecture. The ToP master sends timing packets to ToP slaves. ToP slaves recover the
timing reference from the received timing packets.
The transport network between the ToP Master and the ToP Slave embedded in the BTS
must fulfill certain engineering rules to guarantee proper operation of ToP as
synchronization source such that the stability of the frequency for the air interface meets
3GPP requirements (+/-50ppb). These engineering rules are related to the treatment of
the IEEE1588 ToP packets in the network and SLA values for Packet Loss and Packet
Delay Variation.
Flexi Zone Indoor Pico BTS Product Description
DN09210454 Issue: 01