Verizon outage/rumors/cause

[i0wnj00]

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In SHORT: Integrating CDMA into GSM is HARD. Especially with IMS and VZW being FIRST IN THE WORLD (aka beta-tester for the world's operators) to do it on LTE. Its already perfected I believe on CDMA2000 and GSM (2G/EDGE), UMTS (3G/HSPA+) and now its VZW's LTE turn.

If your analysis is correct then in hindsight, Verizon Wireless should have adopted HSPA+ as a stepping stone. While they have some experience with CDMA and 2G GSM, i think that a nationwide conversion to HSPA+ would have prepared them for running both LTE and CDMA.

At least with HSPA+ and CDMA in place, they would have already the ironed out the qurks with intergrating GSM and CDMA together, instead of starting from scratch.

As for 2GGSM and CDMA on Verizon, IMO that is more or less a half baked solution for supporting the remains of RCC Unicel GSM network instead of a serious effort to learn how intergrate GSM and CDMA.

[Guest 214]

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If your analysis is correct then in hindsight, Verizon Wireless should have adopted HSPA+ as a stepping stone. While they have some experience with CDMA and 2G GSM, i think that a nationwide conversion to HSPA+ would have prepared them for running both LTE and CDMA.

That would have been a waste of time and money and investor's wouldn't have liked that. Overlaying the network with UMTS brings its own set of problems and concerns.

Their network is very large, and we know how long its taken AT&T to overlay their network and they still aren't even close to being finished. They would essentially by deploying two separate technologies, and while it would have helped ease the LTE transition, it still would have issues and cost them money because they would have had to given out all new handsets, and if they shut down CDMA OnStar and the many other telematics user's + the extreme amount of roaming revenue they get from Sprint and other carriers would be lost.

They are doing the right thing by going straight to LTE, its just going to be a hard process.

Going HSPA+ to LTE would introduce problems such as spectrum allocation, legacy handsets, M2M, roaming, and covering the large amount of area's. Plus they would have to deal with signal issues like Telstra in Australia did that took quite a bit of time to fix.

[Guest 214]

I can't wait until they go LTE only with the GSM MAP core and *HD voice*. That would be SWEET.

I understand from the sites I'm reading VZW wants to get rid of the CDMA2000 network ASAP but can't due to legacy users (if engineers had their way...).

Anyways...

They want to get rid of their EVDO mainly, I believe they stated 1xRTT will be around for at least until 2018-2020 because there are so many legacy units on the network, and it is a very stable core network that if VoLTE goes down they can revert to 1X at least. OnStar/Toyota/Hyundai/ect.. all use the 1X voice network for In-Band modem signaling because its so reliable.

[Guest 214]

LTE Fever,

Interesting. If it was a pure data device, in a pure 100% LTE area (100% of their sites have LTE on it) then switching the phone to LTE-only (GSM EPC core ONLY) would make sense...

eHRPD is just a half-hack-half-baked solution to switch to EVDO when the LTE isn't there...

As I understand it eHRPD only handles signaling to from the 1X/EVDO network when there is a voice call and switching to 3G only area when you leave the LTE network!?

Yeah the 4G radio is pure LTE-GSM-goodness..

From the publications I have read thats exactly right. eHRPD is evolved HRPD which in HRPD being the EVDO network. It was supposed to seamlessly integrate into EVDO because EVDO itself is an all IP based network, but in order to accept handover's, they are integrating the EV standard with UMTS based elements mixed in. Its basically emulating a UMTS core for the LTE network to handover to.

When you leave an LTE tower without eHRPD, the data session would completely drop and it would resume once the phone signals the HRPD network and start a new session with a new IP. With eHRPD, the LTE hands down the data session like it would to a UMTS network, and from there it falls to the new eHRPD core and that in turn signals EVDO to continue the session seamlessly.

Its basically the middle man telling both what to do.

When Verizon has the majority of its network and the entire market that the majority of user's would stay in have LTE, its possible Verizon will start signaling the devices to connect to LTE natively which is what they are implying by saying VoLTE will not continue out of the LTE network.

Then if the few remaining user's travel outside large LTE network, it will fall back to eHRPD or possibly just HRPD.

Of course this is all speculation of whats going to happen, but I personally think they will just have the devices connect to LTE natively when VoLTE comes into play and hopefully this is true.

If they wanted to keep the eHRPD core long term, they would implement VoLTE with circuit switched handovers to the 1X network, but it seems they know this is a temporary solution while they are building the network.

[Guest 214]

BTW LTE Fever and others in the industry:
Why didn't VZW overlay their network with a native E-UTRAN/EPC and forgo the eHRPD crap that half fails all the time when they have their LTE network built-out!?

http://developer.att.com/home/commun...f_Services.pdf

There's AT&T's version...

UPDATE: Seems like eHRPD is required for legacy 1X voice calls... All the meaning of voice, 1X, always will be there... And going into 3G only areas.

I believe eHRPD is required for authentication to the 3G/LTE network right now, I am not sure if its required for 1X because that has its own database for ESN/MEID authentication. 1X is never affected during these outages when eHRPD goes completely down and devices can be forced directly to HRPD/EVDO Rev. A so I believe they have left eHRPD out of that equation for reliability purposes.

The LTE network has its own native E-UTRAN/EPC core but the way the device's are setup to seamlessly multi-mode between the two network's since they expect most user's to hit the 3G network in their everyday travels during driving since not ever tower has LTE or power levels haven't been tuned properly in every area, they always have to rely on eHRPD to connect to LTE.

Eventually they should be able to eliminate eHRPD when the majority of the network is LTE capable. Right now its too small though to do so and it would cause many dropped data sessions.

I like the way AT&T is implementing CSFB, its a more basic solution but seamlessly integrates with GSM/UMTS.

To everyone else, in layman's terms

eHRPD is like Sara from the Andy Griffith show . When your LTE phone come's on, it has to make a call, but it cannot make that call directly and has to go through eHRPD or *Sara*, if *Sara* or eHRPD isn't there to connect you, then your call fails and basically all you have is a dead end line and you can't do anything data related.

[ilvla2]

I believe eHRPD is required for authentication to the 3G/LTE network right now, I am not sure if its required for 1X because that has its own database for ESN/MEID authentication. 1X is never affected during these outages when eHRPD goes completely down and devices can be forced directly to HRPD/EVDO Rev. A so I believe they have left eHRPD out of that equation for reliability purposes.

The LTE network has its own native E-UTRAN/EPC core but the way the device's are setup to seamlessly multi-mode between the two network's since they expect most user's to hit the 3G network in their everyday travels during driving since not ever tower has LTE or power levels haven't been tuned properly in every area, they always have to rely on eHRPD to connect to LTE.

Eventually they should be able to eliminate eHRPD when the majority of the network is LTE capable. Right now its too small though to do so and it would cause many dropped data sessions.

I like the way AT&T is implementing CSFB, its a more basic solution but seamlessly integrates with GSM/UMTS.

To everyone else, in layman's terms

eHRPD is like Sara from the Andy Griffith show . When your LTE phone come's on, it has to make a call, but it cannot make that call directly and has to go through eHRPD or *Sara*, if *Sara* or eHRPD isn't there to connect you, then your call fails and basically all you have is a dead end line and you can't do anything data related.

You better hope you don't get Ernestine





Could Verizon have her running the show? LOL