Designing In Dual-Mode: An Interview With D-Link

Will dual-mode phones experience mass adoption? Electronic Design Associate Editor Christine Hintze talks with D-Link Associate Vice President of Technology North American Sales William C. Brown about where single- and dual-mode Wi-Fi phones are going, as well as the design concepts behind the company’s first-generation V-Click handsets.

Hintze: Some studies suggest that Wi-Fi cell phones may soon find favor with consumers, yet many consumers are not yet aware of such an offering. Do you think that Wi-Fi phones will experience mass adoption? If so, when?

Brown: Today, they are early adopters. There are two directions for single-mode Wi-Fi phones:
1) As a low-cost leader to sell service when service providers (SPs) get dual-mode wireless handsets going
2) Personal media players adopt single-mode Wi-Fi voice capability as a feature set

Hintze: Operating a Wi-Fi cell phone requires a decent understanding on the part of the consumer as to how to access a wireless network. How does this affect consumer adoption?

Brown: Beyond early adopters, [customers] that are tech savvy will take [need] a service provider to add additional software interfaces to ease the experience of single-mode Wi-Fi handsets. We are working with some theories today, which will be tested in mid '07.

Hintze: Wi-Fi phones have yet to find broad consumer adoption, yet dual-mode phones are already coming on the market. It would seem that the average consumer would be more likely to opt for a dual-mode phone, as it would minimize their interaction with the network. What are your thoughts?

Brown: Working in both single- and dual-mode product segments, we believe your synopsis is correct. However, every handset manufacturer out there has eye on single-mode because of cost. Take, for example, how much a Blackberry costs without a contract. Single-mode, being the cheaper option, will probably be used to entice the customer to switch over to a dual-mode service plan.

Hintze: EEs have long lamented the difficulties of designing a consumer product as small as a cell phone with more than one radio. How did D-Link approach this in the design of their V-Click phones?

Brown: V-Click is a first-generation [product into] which we have put years of R&D. The issue with Fixed Mobile Convergence (FMC) using automatic handover (GSM<->Wifi) and back is very complex. It is also very expensive to deploy current FMC technology like IMS and UMA/GAN. The V-Click voids the requirement of IMS/UMA/GAN by providing a manual method of changing from GSM to Wi-Fi and back. This also allows the user to control his battery drain when traveling outside a Wi-Fi area. One would just click over, then, to Wi-Fi to avoid using expensive roaming charges. As this automatic handover technology becomes more for the consumer, D-Link has plans to follow.

Hintze: Battery life is a major issue today in consumer electronics. Some product specifications for the V-Click put its battery life as 5 hours for GSM talk and 2 hours for Wi-Fi talk time. What is the standby battery life span? And what did D-Link do during the design process to maximize battery life while achieving dual-mode usability?

Brown: GSM: 72/5 hours as tested. Wifi: 4.5/2.24 hours as tested.

This was one of the strong reasons to provide a manual way (V-Click) to turn on/off the Wi-Fi on the fly.

Hintze: There are mixed feelings among the experts as to whether or not to incorporate cameras, video cameras, etc. into new cell phone designs. According to the product specifications the V-Click does not have a camera, but it does feature video playback and MMS/SMS messaging. What lead to the decision to not incorporate cameras, video cameras, etc. into the V-Click?

Brown: This is first-generation. Over time, cost downs and feature-ups will allow us to fill out the V-Click family.