Okay, thanks...that's a clever (if cumbersome) workaround. I'm not sure (without testing or without having you or someone else confirm for me) whether this solves all the same problems that the 8000's preferred ECI list implementation does, though.
Does it process the Cell Lock list in order (first one in the list is priority 1, etc.)? If the eNB identified by the EARFCN+PCI at the top of the list is unavailable during attachment, but becomes available later, will the UE detect this and switch over, or will we have to force a detach to get it to bounce over? My concern is that you can solve one problem or the other with this implementation, but not both: 1. If you only list one EARFCN for a given PCI, there is no risk that the UE could connect to another eNB pointing away from it at the same cell site, but you are effectively frequency-locking and cannot change channels on eNBs any more easily than before. 2. If you list all EARFCNs for a given PCI, then you can change channels much more easily, but there is a risk that if the eNB that it should connect to is unavailable, the UE will attach to one of the other sectors at that cell site, and won't let go of that attachment until it is manually forced off. The whole point of having this feature is to prevent customers from experiencing poor performance as a result of attaching *and staying attached to* the wrong sector, which results in a call to the support department and manual intervention on our part. I would say that in our case, without any kind of cell lock implemented, if a UE is attached to the wrong eNB, the odds are overwhelmingly good that it will be attached to another eNB on the same cell site, not to another eNB on a different cell site. So I'm not sure that listing all EARFCNs for a single PCI actually helps with that problem at all. -- Nathan From: [email protected] [mailto:[email protected]] On Behalf Of Gabriel Pike Sent: Wednesday, February 08, 2017 1:04 PM To: [email protected] Subject: Re: [Telrad] Handover You can make multiple entries for each PCI. In other words add each channel available under the same PCI. Regards, Gabriel Pike Network Engineering MTCNA DMCI Broadband, LLC<http://dmcibb.net/> [email protected]<mailto:[email protected]> 877.936.2422 Ext. 103 From: [email protected]<mailto:[email protected]> [mailto:[email protected]] On Behalf Of Nathan Anderson Sent: Wednesday, February 08, 2017 3:57 PM To: [email protected]<mailto:[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]> [mailto:[email protected]] On Behalf Of Shayne Lebrun Sent: Wednesday, February 08, 2017 6:12 AM To: [email protected]<mailto:[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]> [mailto:[email protected]] On Behalf Of Nathan Anderson Sent: Tuesday, February 7, 2017 5:27 PM To: [email protected]<mailto:[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]<mailto:[email protected]> <[email protected]<mailto:[email protected]>> on behalf of Adam Moffett <[email protected]<mailto:[email protected]>> Sent: Tuesday, February 7, 2017 12:21 PM To: [email protected]<mailto:[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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