One entry per PCI and frequency.

PCI 1 - 3600

PCI 1 - 3620

PCI 1 - 3640

 

I'd assume the idea is, you probably have a standard set of center channels
you use across your network.

 

Like I said, it's not the greatest implementation, but it's way better than
simply hardcoding to a single channel and hoping for the best.

From: [email protected] [mailto:[email protected]] On Behalf
Of Nathan Anderson
Sent: Wednesday, February 8, 2017 3:57 PM
To: [email protected]
Subject: Re: [Telrad] Handover

 

Okay, on the 7000s, what am I missing?  The "Cell Lock" screen require you
to enter *both* a PCI *and* the EARFCN (the channel), making it effectively
just a more specific channel lock.  And a PCI by itself is not enough to
specifically identify a particular eNB (which is, presumably, why "Cell
Lock" requires that you specify both PCI and channel).  So all that "Cell
Lock" does that the old frequency lock didn't do is make sure that the CPE
doesn't wander off of that tower and onto another eNB on another tower
operating on the same channel.  But you're still hard-coding frequencies
into CPEs, which means that if you need to change channels on an eNB, you
still have to go through all of the CPEs attached to it and change their
programming.

 

Specifying ECI *would* be specific enough to identify a unique eNB, and
specifying an ECI without a channel is exactly what the 8000s allow you to
do.  And because you can set it up so that it isn't an exclusive lock-out of
other eNBs, if the eNB that the 8000 is configured to connect to is down for
whatever reason, it can still attach to the eNB with the next-best signal,
and then move back over to an eNB in its "preferred" list once one of them
is back.  Great feature.

 

-- Nathan

 

From: [email protected] [mailto:[email protected]] On Behalf
Of Shayne Lebrun
Sent: Wednesday, February 08, 2017 6:12 AM
To: [email protected]
Subject: Re: [Telrad] Handover

 

You can lock to Physical Cell ID in the 7000s since .105, I think, though
I'm not sure about having a primary/secondary type setup.  Still way better
than just hardcoding a frequency and hoping for the best.

 

We tried moving to handover when we had some Telrad engineers on-site from
Israel.  We un-implemented it after two days, I think, before they left, and
haven't tried since.

 

I will say, however, that having primary/secondary EPCs set up in the ENBs
is, as the kids said at one point, the bomb-diggity.  In our tests, wherein
we turn off the Ethernet port facing one EPC, the ENB will fail over to the
secondary within about 20 seconds on average.  Much nicer than what happens
when your only EPC just goes away, in our experience, which is the majority
of your UEs hang and require physical reboots.

 

I'm not quite clear on exactly what happens when a primary EPC comes back; I
think what happens is that the ENB notices it, starts using it for new
connections, but doesn't move established UE connections back unless and
until you issue an 'request enodeb-actions
something-something-move-back-to-primary' type command.  This takes a few
seconds.

 

I would like an option to gracefully remove an EPC from service, however;
mark it as 'unavailable,' migrate connections off of it, then you can do
whatever.  Also, gracefully rebooting the EPC with a 'request reset reset,'
which must do something graceful with existing connections, as it doesn't
cause the stuck UE problem, doesn't seem to actually inform the ENBs that
it's now technically unavailable.  These things may all be there already,
and I just haven't found them.

 

From: [email protected] [mailto:[email protected]] On Behalf
Of Nathan Anderson
Sent: Tuesday, February 7, 2017 5:27 PM
To: [email protected]; Adam Moffett
Subject: Re: [Telrad] Handover

 

Not us, yet.  Haven't even tried wandering down that rabbit hole.

 

I will note, though, that CPE8000 firmware has a vastly superior mechanism
for locking to specific eNB than the 7000 does (at least currently), because
it isn't based on frequency but rather Cell-ID.  So you can change channels
on your eNBs and your locked-down 8000s won't need to be reconfigured.  And
you can have multiple Cell-IDs in the preferred list, and the cell-lock can
either be hard (only ever connect to this Cell-ID) or soft (prefer this
Cell-ID; if it isn't available, feel free to connect to something else, but
then check every X minutes to see if something in the preferred list happens
to be broadcasting again).

 

It'd be nice if this also came to the 7000 at some point, but then again if
X2/handover is either working right now or close to working, maybe they
consider putting more effort into the 7K firmware a waste of time.

 

-- Nathan

 

  _____  

From: [email protected] <[email protected]> on behalf of Adam
Moffett <[email protected]>
Sent: Tuesday, February 7, 2017 12:21 PM
To: [email protected]
Subject: [Telrad] Handover 

 

Is anybody using handover successfully?

 

I'm looking for a way to keep UE on the best eNB without locking in specific
frequencies.

 

 

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