Traffic management and offload - diverging solutions

One of the major trends I'm seeing at the moment is that of mobile network offload - typically "dumping" traffic onto WiFi or other networks to avoid congestion from mobile broadband.

I'm expecting it to be a huge feature of this year's MWC / 3GSM in Barcelona.

But at first sight the offload trend seems to be a confusing mish-mash of technologies and techniques, all designed to reduce the impact of bulk traffic on cellular networks, but applied in very different ways. I'm trying to start to categorise these various areas, and also work out how they are being prioritised.

One important fact to note is that "congestion" is itself quite complex. It can be congested radio (RAN) networks in terms of downlink capacity, uplink capacity or signalling. It might be congestion in the backhaul from a cell-site to an aggregation point or the core network. It could be various elements of the core itself - SGSNs, GGSN and so forth. It could be a supporting IT system that handles IP networking (eg the DNS), or the billing/rating engine.

And then we have the various classes of solution. I'm still thinking about a full taxonomy (and terminology), but an initial starting point might be:

- Macro offload onto femtocells (in homes, offices, hotspots or outdoors)
- Macro offload onto WiFi (in homes, offices, hotspots or outdoors)
- Local IP breakout for WiFi & femtos (in the premise or at the broadband DSLAM / cable head-end)
- Managed offload (eg where the fixed or cable access provider, used for the WiFi or femto connection, actively assists in the offload process)
- Macro backhaul offload (eg direct connection to a cache or CDN for "bulk" Internet video)
- Core network offload / bypass
- Content compression (eg video format transcoding)
- Traffic-shaping (eg selectively degrading / capping specific flows or traffic types - sometimes misnamed as "applications")
- Policy control (prioritising specific users / subscribers, or administering specific profiles to some)
- Optimisation of capacity utilisation at the IP level, by changing the TCP protocol or packet scheduling, or by introducing "scavenger class" traffic


EDIT - MAY 21st - New research paper published - see below.

I'm sure there are others - while these segments can undoubtedly be fine-grained more as well. The bottom line revolves around a reduction or delay in the need for capex to enhance network capacity, and as a corollary an improvement in the more nebulous quality of "user experience" - at least for the bandwidth non-hogs.

What's not clear to me is which of these techniques is the most effective or important overall. I suspect it probably varies by operator, maybe even by cell or time. From a top-level ROI perspective, which of them enables spending on network upgrades to be minimised? Or perhaps introduces new revenue streams.

My gut feel is that for networks dominated by *PC-based* mobile broadband, the best option is some form of radio offload. All notebooks have WiFi, and they also tend to have the most complex applications and mashups, as well as being able to spot any degradation of quality or operator "interference" most readily. Having a PC user say "hang on - why's this video performing better over my ADSL line than over my HSDPA, what's going on?" is likely to lead to damaging PR, if you're trying to present your mobile broadband as a direct replacement for fixed connectivity.

I reckon it's simpler and safer just to dump PC traffic to a standard Internet connection as close to the device as possible. For iPhones and some smartphones, the same may be true. But for other devices, it may make more sense to route the traffic via the operator core and play around with subscriber policies, or adapt traffic at the application layer. But I'm sure there are exceptions in both cases - for example, where a PC is actually an operator-controlled netbook.

I'm going to try and resolve the picture more clearly over coming months.

EDIT - MAY 21st - New research paper published - see below.

NEW Mobile Broadband Traffic Management Paper

NEW Broadband Business Models Strategy Report

Debating the use of the term "4G"

I'm noticing an increasing use of the term 4G to describe either WiMAX or LTE networks.

It makes me wince, (although I've probably fallen into the "convenience trap" myself a couple of times).

Yes, they're both different to current versions of 3G, and use techniques like OFDMA - but so what? That doesn't make them 4G any more than it made EDGE (part of GSM) into 3G.

From a purist point of view, 4G doesn't yet exist. 3G refers to the families of technologies covered by the ITU's definition of "IMT 2000". 4G is expected to be the term used for the forthcoming "IMT Advanced" specifications currently being thrashed out by ITU, for which there are two prospective main candidates - LTE Advanced and WiMAX variant 802.16m.

Any use of the term 4G at present is therefore pure marketing fluff. A lot of WiMAX and LTE operators and device/network suppliers are fluffing, in an effort to come up with a brand that conveys evolution and new-ness.

The irony that the WiMAX community a huge amount of time and effort to convince ITU that their technology was in fact 3G (and therefore allowed to use IMT-2000 spectrum bands) seems to be ignored.

My instinctive reaction is to "deduct some credibility points" from the offenders when I see their announcements, or talk to their executives. If they are that sloppy that they mis-describe their technology, then surely it's reasonable to assume they're also sloppy about other aspects of their business?

Yet after a while, the practice may become so entrenched that even the more sensible participants have to wince, take a deep breath and mis-use the term 4G as well, so as not to lose out in the marketplace. If you can't beat them, you have to join them.

So, some solutions:

1) Any operator launching HSPA+ should also describe it as 4G. Well, if it's got MIMO, then it's *also* different from existing 3G. If the OFDMA guys are going to pick arbitrary definitions, then they can hardly complain when you do the same.

2) An operator with a brave PR department (and possibly a good legal team) should publicly take rivals to task for using 4G, using terms like "misleading", "lying", "sloppy" or "false advertising". Potentially, some of the current providers are on thin ice with regard to consumer protection law - although as the ITU hasn't yet called IMT-Advanced "4G" the response is probably that there's no strict definition in place.

3) Lobby the ITU to hurry up and call IMT-Advanced "4G" while it still has the ability to do so, before it gets lost in the marketing waffle.

As for me - well, I'm going to rely on the body language and non-verbal communications of people I speak to. If someone says 4G when describing their new LTE or WiMAX gizmo, but slightly winces, or rolls their eyes, or grits their teeth... then I'll give them the benefit of the doubt. But if they brazenly, unashamedly and unequivocally claim the 4G label for their 3G goods, I'll definitely be looking closely to find what else they've glossed over.