A commonly-asked question around femtocells is the question of what advantage they confer to data devices, in the case where both the device and the broadband gateway also have WiFi access. Is there any advantage in keeping the data on the femto connection, given that many millions of people are now routinely using WiFi set-ups with security keys & SSIDs, without much hassle or confusion?
I've been thinking about this, as it also fits with some work I've been doing on offloading 3G cellular traffic, and the role of fixed operators (DSL/cable) in providing additional capabilities or grooming services, going from purely independent offload, to a more collaborative "managed offload" scenario where the fixed and mobile operators work together, even if they are not sister companies.
One scenario I can envisage is this: a homeowner has a relatively low-tier home broadband service, say a 4Mbit/s connection, although the local copper could support 10Mbit/s. Now, consider if the user purchased a mobile broadband service offering "up to 7.2Mbit/s", for which the operator also supplied a femtocell in the hope of offloading some of the traffic generated while the user is at home.
There is is an argument that attaching the 7Mbit/s femto to a 4MBit/s ADSL line is actually against consumer protection law - the customer is legitimately paying money for a mobile broadband service which, at least theoretically, should be able to get to 7Mbit/s. If he uses his laptop or smartphone at 3am next to the cell tower, he should be able to attain peak speeds. But with the femto, it ceases to be even theoretically possible, because the backhaul won't support it. Potentially, the connection would *slower* than if the user just unplugged the femto and went back to the macro coverage.
It's not really the operator's fault - the customer has chosen to have a low-spec ADSL service. But the experience is unsatisfactory nevertheless.
However, now consider that the mobile operator pays a small sum to the ADSL provider to "over-provision" capacity to a certain IP address range (ie the femto gateway). Perhaps $2 per month to permit bursts of headroom up to a total 8Mbit/s, as long as total volumes don't exceed 2GB.
Everyone is a winner in this scenario - the user gets blazing-fast connections via the femto, which actually perform better than his own WiFi. The mobile operator offloads more traffic & has a customer with more loyalty. And the fixed operator gets a bit of extra revenue which pretty much goes straight to the bottom line.
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An then the operator upgrades his macro net to 21 Mbps (and end of this year to 42 Mbps, next year to 84 Mbps and later to 168 Mbps and LTE). Should the operator swap my femto every year free of charge and upgrade my ADSL to follow his macro speed...? Or will the user leave his house every time he wants the best performance?
ReplyDeleteAh, but by the time LTE finally rolls out you'll have FTTH capable of supporting symmetric Gigabit Ethernet.... but I bet that even then, some people will still go for the cheapest (or free, municipality-supplied) broadband package.
ReplyDeleteMore seriously, one of the largest issues for femtocells is that almost all the devices that really drive traffic also have WiFi, so ideally there need to be differentiators. Less interference & more range are possibilities, also femto-based services. But the scenario I suggest here actually makes mobile broadband look like a premium service compared to ADSL+WiFi and could potentially drive substitution of usage and/or revenues, while still benefiting from offload.
The other option here is that the femto traffic could be zero-rated and not count towards the fixed-broadband cap.
ReplyDeleteNot much of an issue in uncapped / high-capped markets like the US (eg 250GB on Comcast I think?) but in some markets it's as low as 10-20GB per month, so "paying double" for 2GB of 3G traffic being backhauled is a significant issue.
So instead of today's users that receive a fraction of 7Mbps from the shared tower bandwidth, they can now get the full 7Mbps from their femtocells. Excellent! Is the mobile data network core provisioned for all of these 7Mbps subscribers? Likely not... Does the necessity for a massive investment in GGSN and the services LAN capacity have any bearing on the slow rollout of services? Maybe...
ReplyDeleteHigh bandwidth femtocell users are why operators must consider femto aggregation architecture scalability, and consider breaking out Internet traffic before the GGSN and services LAN. Both will support high bandwidth users and improve data service performance, and both will improve operator data service margins.