Handsets are already getting to market under-performing in certain areas – and tests for certain applications are still nascent. Adding LTE to the mix will only put more pressure on the test community, as they support developers working under ever more intense pressure

The increased capability of LTE devices presents a similar increase in the degree of complexity for manufacturers bringing these products to market. Simpler designs could once be tested at the manufacturing stage; however, the costs of addressing problems late in the development cycle are likely to prove unsupportable today, and the requirement has shifted to the R&D phases to catch problems earlier.

The progress of the standardisation work for 3G LTE is based on a set of high-level requirements, the principal aim of which is to further improve service provisioning and coverage, but at a reduced cost-per-bit compared to 3G for both operators and users. All this is to be achieved within the context of an enhanced user experience, operational flexibility that covers both existing and new frequency bands, improved data rates and reduced latency. As such, 3G LTE will provide the major leap forward, all of which brings with it significant testing challenges.

The compressed timeline for LTE standards development is reflected in the schedules for LTE product development. As specifications for the LTE radio interface stabilise, equipment manufacturers have begun to work on components for LTE base stations and user equipment. Operators have to upgrade their core networks to support LTE, and they undoubtedly want to have user devices available in quantity at the time of commercial launch. Suppliers of design and test equipment have to keep pace to provide the tools necessary for these tasks. Because of the newness and complexity of LTE technology, there are a range of engineering design and test challenges to address in the different parts of the LTE infrastructure:
RF: The variable channel bandwidths specified for LTE increase the system's flexibility and capability but also add to its complexity. The use of multiple antenna configurations and OFDMA to support high data rates adds further complication, although it's expected that by the time LTE products reach the RF testing stage, test engineers will be able to apply lessons learned from implementing MIMO and OFDMA in WiMAX. However, the use of SC-FDMA in the uplink will result in some challenges unique to LTE. With performance targets for LTE set exceptionally high, engineers have to make careful design trade-offs to cover each critical part of the transmit and receive chain.
Layer 1/Baseband:  To support the high data rates that are the goal of LTE, exceptionally large amounts of processing power are needed, particularly in the baseband, where all the error handling and signal processing occurs. Baseband designs will be modeled using PC simulation on both the UE and network sides, and reduced-speed emulation of hardware prototypes is also happening.
Layers 2/3: LTE Layer 2 is split into three sub-layers, including the Medium Access Control (MAC) and Packet Data Convergence Protocol (PDCP). Design challenges at this layer will be the handling of significant amounts of data in the PDCP and implementation of the 2ms MAC turnaround time. Layer 3 handles the main service connection protocols. Detailed specifications for both of these layers are still under discussion. Although early product development can be accomplished with simulation of these layers, the integrity of a device design cannot be determined until they are properly integrated with the baseband and RF sections at full operating speed.

Along with LTE-specific challenges are those associated generally with wireless design. Overall system performance depends on the performance of both the baseband and RF sections, and each is associated with particular impairments-for example, nonlinearities and noise figure in an RF up-converter or down-converter, phase and amplitude distortion from a power amplifier, channel impairments such as multi-path and fading, and impairments associated with the fixed bit-width of baseband hardware.

Not the least of all these challenges is the fact that LTE is an evolving technology, and as such is open to change and interpretation. The early availability of conformance tests will help alleviate interoperability issues and provide basic testing. However, from day one of commercial launch LTE must deliver an outstanding user experience in terms of voice quality, quality of data services, and battery life. For that reason comprehensive functional testing and real-world verification of LTE products is essential.

This in turn has put pressure on the test community as it is faced with not just testing protocols that are more complex, but also with dealing with technologies that are not stabilised in fixed standards. Nor are the challenges "merely" on the physical layer – pressure is being applied to produce tests in layer 2-3 that will ascertain the likely user experience of phones, rather than merely give a pass/ fail on.

At the moment, some European operators are reporting return rates on certain handsets of 50%, according top Spirent's Nigel Wright, Vice President of Wireless Product Marketing. But the surprising thing is, the reason for return has to with something as "simple" as handover.

"We talk to large operators in Europe, and 50% of some models are being returned – and these models are also the ones that are dropping calls the worst. And the biggest reason for dropping a call has been in handover failure," Wright says.

This is interesting because, as the industry looks forward to LTE, in all its OFDMA, MIMO, beam forming, 4×4 antenna complexity, the number one issue in returned handsets appears to be something this magazine was covering back in the early years of the decade – namely how to deal with handover between 3G and 2G networks.
Wright agrees.

"It is spectacular that this was not sorted out years ago. We were very surprised, but if you ask operators what their number one issue is right now they consistently say it's this. Most of them now keep a blacklist of handsets with performance issues."

As 3G LTE is an evolution of existing UMTS systems based on W-CDMA and will also fully integrate with existing GSM/GPRS/EDGE networks, seamless handovers will be critical to the gradual rollout of the first 3G LTE networks and deployment of the first LTE mobile devices. Such handovers might simply be inter-cell between neighboring 3G LTE cells or they could be handovers to W-CDMA or GSM/GPRS/EDGE as a user moves in or out of LTE coverage.

Wright thinks that much of the problem could be to do with a "GSM mentality", in which operators have always trusted and relied on conformance testing. In the CDMA world, where testing was less standardised, operators have long developed out their own test environments, in-house, to assure performance. So are European operators starting to take more responsibility for their own devices under management?

"They are starting to look at it." Wright says. "but I wouldn't say it's really been seen widely yet. There's still the GSM mentality of "if it's certified then it's good".

Yes even though handsets may have achieved certification, that is no guarantee of a consistent level of performance – and hence user experience – across handsets.

Here's Wright again. "It's really about achieving a minimum level of performance, of standardisation compliance. Yet in recent benchmarking for an industry analyst in the USA, we saw devices operating under identitical network conditions achieve two times the data rates of others, depending on the chipsets involved and the efficiency of the network and channel-related algorithms. That's a big difference.

"Significantly, we have started seeing large operators develop their own acceptance tests, versus accepting the terminals as they are. AT&T has put in a pretty significant back office and its own data performance testing."

But if HSPA has been showing up performance difficulties, LTE will place even more concerns on the operator and handset manufacturer side.

"Historically, new technology roll-outs have been subjected to delays, often due to problems experienced when the new technology mobile devices are tested against the new technology networks," says Aeroflex's Phil Windred.

For example, in order to obtain the all-important performance advantage for higher data rate mobile applications, the 3G LTE specifications will be based on a switch from W-CDMA to OFDM (Orthogonal Frequency Division Multiplexing) modulation technology. This represents a significant change at the very lowest level of the radio communications and achieving synchronisation will be a major challenge.

Complete visibility into the very lowest layers of the radio modem will allow users to diagnose the actual cause of a synchronisation problem rather than just knowing that synchronisation has failed.
Without the higher layer protocol, it is necessary to completely configure the physical layer using test scripts. As a consequence, many early test failures may not be the result of real problems, but rather by a mismatch in the setup between the prototype under test and the test equipment. With hundreds of parameters that need to be selected, the risk of a mismatch is significant.

A further implication of physical layer testing when the higher layer protocol is not available is that test automation is essential to ensure extensive and complete testing. The incorporation of test script configuration tools will allow the easy generation of all scripts needed to select the different configurations and tests. These various scripts can then be initiated by a test controller as required to synchronise control of the prototype under test and the test equipment. It will be possible to alter parameters in real time to enable test coverage to be extended across the wide range of different configurations used in a live system both in relation to test of the 3G LTE network and test of early 3G LTE prototype mobile devices. This will allow the early detection of software bugs associated with particular parameter values that will not otherwise be found until much later in the design cycle when diagnosing and rectifying errors tends to be much more expensive.

"With the current method of working for conformance testing, adding LTE capability means the scope of the tests required will end up being massive, and could still not cover all the performance envelope of the device," Wright says.

So how will the industry deal with the great scope of LTE device testing?
"I'm not sure how this is going to develop. Device manufacturers may be stuck with huge manadatory testing requirements, and operators cannot be sure even then if they will catch it all. It's going to be interesting to see how test approval evolves over the year. Something needs to change."

How will Mobile TV work when we hide out indoors or in the subway? Dr Peter Raabe, Radio Frequency Systems Global Product Manager – Wireless Indoor Solutions, explores the options

Just as consumers expect mobile phone and wireless data coverage everywhere indoors and underground, they will have the same expectation of broadcast mobile TV and WiMAX services–particularly since these will be received on the same multi-functional handsets. In fact, it is expected that the vast majority of mobile TV and wireless data interaction will take place ‘indoors', in venues such as homes and office buildings, plus busy public metros, shopping centres and airport terminals. Consequently, carriers are already exploring the level of coverage that will be required in these so-called confined spaces, and how to achieve it.

The practical approach will be to obtain as much coverage as possible from the outdoor network, which will be the starting point for deployment. But, although people's homes and some office buildings may be serviced in this way, a great many other key venues cannot be adequately penetrated by the outdoor network signal. This calls for the deployment of dedicated RF infrastructure to distribute the signal indoors.

Fundamentally, the principle of achieving wireless indoor solutions for broadcast mobile TV and WiMAX is no different from 2G, 3G and WiFi networks. Indeed, many key buildings around the region already have confined coverage infrastructure in place to support mobile phone, wireless data, and various radio services. These generally take the form of passive or active broadband distributed antenna systems (DAS) that support multiple services and carriers, and which now can be leveraged to provide coverage for broadcast mobile TV and WiMAX as well.

Adapt and adopt
One of the challenges will be adapting the existing systems to provide optimum coverage for these next-generation services. Take broadcast mobile TV in the first instance. Digital video broadcast to handhelds (DVB-H) mobile TV services are likely to be deployed in either the UHF or S-Bands. The UHF band (~470-720MHz) is close to the 800 and 900MHz cellular bands, so similar RF signal propagation and cable loss characteristics can be assumed. The S-Band (~2200MHz) is more likely to exhibit behaviour similar to the UMTS 2100MHz band.

WiMAX, on the other hand, operates at frequencies up to 6GHz–including the licensed and unlicensed 2.3-2.7GHz, 3.3-3.7GHz and 5.1-5.8GHz bands. At these higher frequencies, both signal propagation and cable loss characteristics are likely to be quite different, providing new challenges for coverage planners.

The other coverage planning issue that must be taken into account is that of how strong the signal needs to be for handset reception. This will vary significantly depending on whether the subscriber is stationary (such as sitting in an airport terminal), or moving (such as sitting on a subway train). In addition to signal level, both mobile TV and WiMAX reception at high speeds are highly dependent on the number of signal carriers and the type of signal modulation used.

The interaction of the indoor ‘microcell' with the outdoor network must also be considered in order to minimise interference. It is likely that mobile TV services in a given region will be allocated a single RF channel operating in single-frequency network (SFN) mode. Owing to licensing restrictions, this is anticipated to incorporate any indoor microcells as well as the outdoor network.
Conventional outdoor SFNs operate using complex signal timing and strict power levels to avoid co-channel interference. Although network planning is a challenge, the finely tuned network is essentially static once on-air. The introduction of indoor SFN microcells creates a dynamic environment that must therefore be carefully controlled, lest the balance of the total SFN is disrupted. Conventional indoor planning targets the indoor signal being stronger than what penetrates from outdoors, but when operating in SFN mode it is also important to exert strict control over the signal timing and power levels to ensure optimal coverage is achieved without interference.

Infrastructure evolution
Despite the broadband nature of much of the existing RF infrastructure, there is still much development work being done to allow systems to be upgraded in support of the new services. The heart of an indoor network is typically a broadband passive DAS, comprising broadband radiating cable or a distributed antenna network, which provides contoured RF coverage of a given confined area. These have evolved to be ideally ultra-broadband, allowing all services from 30MHz to 6GHz to share the same passive distribution system.

Wireless indoor solutions also incorporate many different active components that need to be fully functional in the new frequencies and bandwidths specified. These include repeaters and amplifiers to support RF-over-fibre systems, which are utilised in larger buildings and complexes where purely passive infrastructure is insufficient. In addition, methods of collecting the mobile TV or WiMAX signal for distribution indoors need to be considered. These typically include, besides BTS/transmitter combining systems in multi-band multi-service applications, either an off-air repeater and donor antenna assembly, or else a dedicated ‘customer premises equipment' (CPE) installation in the case of WiMAX.

As both WiMAX and mobile TV technologies gather momentum, the fact that consumer interaction will take place to a large extent indoors cannot be overlooked from both a network revenue and customer satisfaction point-of-view. This means the need for wireless indoor coverage has emerged as an essential factor to be considered in the overall business case. The successful realisation of such wireless indoor solutions will demand careful network planning and optimisation of both indoor and outdoor networks, supported by state-of-the-art wireless infrastructure.

Never mind TV – get into video

vTap from Veveo is a service that searches and indexes 115,000 web sites that carry large amounts of mobile video – totalling about 150 million video clips. It then encodes those videos on the fly to users who request them from their mobile device, using their vTap application. Its deployment could help operators unlock latent demand for access to user generated videos on the web, according to Guru Pai, VP of Marketing and Business Development, Veveo??"The free web video segment is a domain that's exploding," said Pai, "but it is disorganised and fragmented. We organize and find content, so we can deliver relevant video to our users regardless of whether they have carried out a specific vide search or are just browsing for content."??"Veveo has been active for a while in the internet but we now plan to do this in the mobile domain," Pai said. "There is increased complexity in terms of user input and display, but a user can find and view any content on the web in our index and then play it on their phone."??Users can either set up a profile on vTap, allowing the service to build up a list of recommendations and so on, or they can browse the index which is organized into about three million or so topics. All the main free internet sites plus news providers and TV sites are included in the index, Pai said.. The service carries out the on the fly transcoding and matching to which player the device has. ??Users can either take the service as a client on their phone, or as an xhtml solution. Pai said Veveo has an announced agreement with Motorola to include to client in its handsets, and has others agreed with other manufacturers that he can't reveal. The application would be somewhere inside a handset Video menu structure, he reckoned, or even on the browser page itself. ??Veveo's business case is to make money through advertising, with Pai currently saying it is in "audience building" mode. ?"Several ad networks think we've got something different," he said, "because either we have user profiles or targeted user queries. We can interleave ads with search requests or have ads on each xhtml page to interface with the rest of the mobile advertising industry."??As for the operators – they may need to change their business approach to video, Pai admitted, to benefit from such an app. If you look at operators like Verizon, it has about a thousand videos in a walled garden at any time, we have 150 million in our index" he said.?"I think operators are trying to figure out the video market. For linear TV they can address that through broadcast mobile TV, which has its place. But the non-linear user generated content world has hundred of millions of videos which is something mobile operators have not taken advantage of. Our value add is to work with operators to help get them addressing that audience. But today they are not doing a good job of monetizing that big audience for web video to the mobile device."??Pai said that vTap can interface with Facebook or other social networking site APIs to integrate people's profile into the mobile world.??"The science behind our services is very non trivial," Pai said. "It's not just an index and a simple search engine."??Currently Veveo says it has 500,000 users in either alpha, beta or some form of pre-launch usage. The company has attracted $28 million so far from VC, has 55 employees and was founded in late 2004.

Mobile Advertising – great white hope or flash in the pan? Avichai Levy and Yehuda Elmaliach look at the opportunities and challenges around mobile advertising, and explain how mobile operators can ensure their place as winners in a sustainable, successful mobile advertising market

Strategy Analytics predicts that mobile advertising will represent a fifth of global spending on Internet advertising by 2011 and will generate $14.4 billion of revenue, so it's easy to see why mobile advertising is being hailed as a major opportunity for the future. But who will be the beneficiaries of this upsurge of interest? Will it be the Internet giants like Google or Yahoo or will the content providers and brand owners reap the rewards, or perhaps this time the wireless operators will grasp the opportunity. I'd like to think that the mobile operators will heed the lessons earned by ISPs in failing to exploit the Internet advertising wave and make sure that they don't become just the dumb bit pipe vendor whilst the other players run off with the major spoils.

Snakes and ladders
At present the winners and losers are hard to predict. We are seeing a number of mobile operators dipping a toe in the water with pilot projects and Google has been quick to enter the fray by offering Ad words on the mobile phone as a default option to all its advertisers. The stakes are clearly high as 2007 saw the jostling for position by major companies in M&A activities such as Microsoft's acquisition of ScreenTonic, Nokia purchasing EnPocket and AOL snapping up ThirdScreenMedia, in a bid to buy in expertise in the mobile advertising arena. One thing is for sure, the traditional media owners in the print and broadcast world are right to be worried as industry experts predict that 2008 will be the year when advertisers start to earmark a significant portion of their advertising funds for mobile and online advertising.

A note of caution
Yet in this rush to capture the hearts and minds of the mobile user buoyed up by the encouraging signs in mobile content downloads, mobile operators are right to approach the matter with a degree of caution. A recent Forrester Research report discovered that although 79 percent of consumers find the idea of mobile ads annoying, consumers will happily engage provided that marketers deliver valuable information or content. So, whilst advertisers celebrate the mobile media for its ability to deliver interactive personal messages to the individual, the mobile operator needs to consider the user experience and respect their right to privacy. If the advert becomes intrusive or annoying or spoils the user's enjoyment of the music track they are listening to, or the video they are downloading, it could be counterproductive and actually cost operators' their customers.

Until now the main focus for mobile advertising has been on text ads and mobile web banners. Indeed the Mobile Marketing Association's only guidelines on mobile advertising exclusively focus on this approach. It's our belief that other rich media experiences such as Video (live and on demand), MMS, rich media WAP or In-Game offer greater promise for mobile ads and the opportunity to enrich the user experience and offer the advertiser a multi-channel approach which is likely to produce better results overall. Such an approach also lends itself most easily to the ad-funded content model.

Ad-funded Content
Any debate about mobile advertising would be incomplete without considering this model and I'd like to examine it from the operator, the advertiser and the user perspective. Firstly from the operator's perspective, who has the chance to supplement subscriber revenue with advertising revenue. As we know from other more traditional mediums the potential for advertising can offer substantial opportunities for a large and diversified income. Certain services lend themselves better than others to these kinds of promotions. Voice services for example are unlikely to be affected, but web 2.0 services can allow consumers to consume content for free based on an agreement to receive certain advertising messages. An example of such a service that could potentially be revolutionised by ad-funded content is mobile TV or "You Tube-like" services on the mobile. Users have expressed reluctance to pay to receive these services but the option of enjoying them for free at the advertisers expense is likely to prove more enticing.

But what about the advertiser? How compelling a medium will the mobile one prove to be? What will they need to convince them to spend their advertising budgets on this relatively untried new vehicle? Two of the key challenges for mobile operators will be to ensure the quality of experience is uniformly good for the user and that the brand itself is portrayed accurately and of a sufficiently high quality to satisfy the most discerning marketing VP. Unlike the Internet the mobile medium has a huge diversity of devices out there with different specifications and capabilities. The operator will need to be able to convince the brand owner that his brand will be communicated at a sufficiently high quality irrespective of the user's device.

Targeting and reporting
Another key requirement of the advertiser will be the need to ensure that the information is accurately targeted based on behavioural, geographic or demographic criteria and that they will obtain reliable measurable results. Since the mobile medium doesn't have the simplicity of the cookie to provide this service, the challenge of providing the brand owner with reliable usage statistics represents a significant challenge for many operators trialling mobile advertising services today. Mobile offers the potential for an interactive dialogue between the advertiser and the consumer and the ability for immediate results. Yet until the operators can provide the reassurance of real measurement metrics to advertisers the service won't take off.

Self-targeted viral advertising
From the users' perspective we've heard mixed reactions. But as yet there is little in the way of industry-wide regulation governing the do's and don't of mobile advertising. One area that we firmly believe to hold the potential for dramatic growth is the area of viral marketing in the mobile medium. Mobile communities such as MySpace and Bebo offer the potential for self-targeted advertising where users forward offers and content on to other members of their group. This offers the potential to extend the impact of a campaign beyond the operators own captive audience and identify people with similar interests, which could in turn be targeted by that operator with offers linked to that subject matter. What's more the recipient is far more likely to react positively to a message from their friend of colleague than from the operator or advertiser.

Enforcing user policies
So why you may ask hasn't mobile advertising already taken off in a big way? For the operators particularly there is a lot to win or loose. If they get it wrong they could risk alienating their customers, if they get it right it could offer a welcome new revenue stream. In the Internet environment the focus has been primarily on reaching the largest number of potential customers in an anonymous way. Mobile is different – it's much more personal. In the first place the operator has to reassure the user that if he opts out of receiving mobile advertising, that promise will be honoured. With no industry regulation determining how often an advert should arrive on a user's device, it is down to the operator to ensure the user isn't deluged with adverts and that policies governing the regularity of ads are strictly enforced.

To protect the user experience and ensure that only relevant ad content arrives on their screens, the ad solution they deploy has to be capable of leveraging the copious amounts of information the advertiser already holds on the customer by interfacing with their existing CRM solutions as well as other internal services such as Location Based Services, so that the advertising they receive is relevant to the recipient. The operator also needs to consider the ability to link to other off-portal content. Offering an advertiser the ability to combine access to off- portal content such as CNN mobile, with accurately targeted behavioural, contextual and demographic information would be an alluring prospect and enable the operator to charge up to ten times higher a price than an external ad seller or Off-Portal aggregator.

Protecting the user
So in summary, what are the key opportunities and risks associated with mobile advertising? For the mobile operator protecting the privacy and interest of their subscribers is paramount. They are legally bound to maintain their users' confidential data in-house and not sell it on to the highest bidder. There are, as we've seen, some interesting lessons to be learned from the Internet advertising experience. But the mobile medium holds some major differences and technical challenges to overcome in order to exploit the diversity of devices in the market. Another key prerequisite is the need to ensure a high quality experience for the user and fulfil the brand owner's specifications of how their logo or brand should be represented. There are numerous opportunities out there to be investigated using multi-channel, rich media such as video and MMS that are still largely being ignored and
the potential for leveraging self-targeting viral advertising over mobile communities is immense. We only hope that the mobile operators recognise the goldmine that they are sitting on and are ready to make sure that they and not the Internet search engine providers are the ones to reap the rewards.

Avichai Levy is VP Marketing and Yehuda Elmaliach CTO of Mobixell, a provider of mobile multimedia and advertising solutions (www.mobixell.com), and members of MMA (Mobile Marketing Association)