내가 일하는 회사가 머 하는곳인지 나 말고 더 잘 말해주는 인간들이 있다..난 머 하는지 모르지만..
BY BRUCE MEYERSON
The Associated Press
April 26, 2005
NEW YORK -- What do you get when you combine Voice over Internet telephony, Wi-Fi wireless access and cell phones?
Aside from an acronym-induced headache, you get yet another new telephone technology with the potential to concuss an industry already whipsawed by tectonic change.
That might sound a bit dramatic, especially coming from a business known for tall predictions. Skeptics say it remains entirely unclear how and when VoIP, or Voice-over-Internet-Protocol phone service, will intertwine with cell phones and wireless Internet access -- or whether any part of the business will suffer as a result.
Yet the appeal is obvious.
Imagine how nice it would be if you're talking on a cell phone when you arrive at home or the office and the call doesn't cut off or turn fuzzy when you step inside. Instead, the call passes without interruption from the cellular network to the wireless Internet signal inside the building, as imperceptible to the user as when a call gets passed from one cell tower to the next.
Would that be the magic bullet that persuades more people to discard their old-fangled phone lines and go all-cellular? For those who already have replaced their regular phone service with VoIP, would there be less of a reason to keep two phone numbers if a cell can pull double duty?
Opinions vary, of course. At this point, the pros cannot even agree on what to call this technological mixture, with possible names ranging from VoWF and Vi-Fi to bigger mouthfuls like wVoIP, VoWiFi and VoWLAN.
Nevertheless, few players in telecommunications doubt that the industry's fastest-growing sectors are destined to converge.
Top equipment makers already are placing bets on the outcome, including Motorola, Nokia, Siemens and Alcatel. So are a growing number of cellular service providers, mindful that upstarts are trialing mobile VoIP, yet apprehensive about the impact on profits.
Many of these companies collaborated on a new standard, Unlicensed Mobile Access, that governs the handoff of phone calls between cell towers and Wi-Fi access points. In February, UMA was adopted by an industry body that sets standards based on GSM, one of the world's two dominant cell technologies. Standards groups also are adapting a network technology called IMS, for IP Multimedia Services, for passing phone calls between cellular and Wi-Fi networks.
UMA trials are under way with two cellular operators in Europe and one in United States, said Steven Shaw, director of marketing for Kineto Wireless, a provider of UMA network and handset software.
So far, only two UMA-enabled handsets have been announced, both by relatively unknown device makers. However, recent announcements by Royal Philips Electronics and Texas Instruments that they're making integrated cellular/Wi-Fi chipsets are a sure sign of demand from cellular operators.
These developments likely won't translate into full-blown VoIP-enabled cell phones until at least later this year, if that soon. As an interim step, simpler renditions of wireless VoIP already are available.
On the most basic level, the collision of VoIP and wireless can mean little more than a souped-up version of the cordless phone: The wireless signal is carried between a cordless handset and a Wi-Fi router connected to a high-speed Internet line rather than a base station plugged into a phone jack.
Net2Phone has been selling a $175 wireless VoIP handset to go with its VoiceLine service since October. VoIP leader Vonage Holdings plans to follow suit later this year with a lower-priced handset.
These devices don't provide cellular's freedom to wander afar, but the combination of wireless and VoIP can be far more potent than a mere cordless phone.
The Net2Phone handset can be configured to connect with more than one router, so a customer can use the same device and VoIP phone number at multiple locations, such as home and work, and any other noncommercial wireless hot spot. Vonage plans to add compatibility with Wi-Fi services sold at retail locations such as coffee shops and airports.
But what if you don't want to carry both a cell phone and a wireless VoIP handset?
For now, the only option is to buy a PDA equipped with both a cell phone and a Wi-Fi transmitter, then download a third-party application to connect with a VoIP service when you are near a hot spot.
However, there aren't many dual-radio PDAs on the market. Until recently, nearly all were based on Microsoft's Pocket PC operating system. As a result, most VoIP applications for PDAs are written for the Pocket PC platform.
In the United States, there are just two Pocket PCs with cellular and Wi-Fi radios: the iPaq H6315 from T-Mobile and the Siemens SX66 from Cingular. Elsewhere, there is only the Motorola MPx in Asia.
Industry players say the timing will depend most on wireless carriers, who not only need to test the new technology but also overcome hesitations about convergence.
For many carriers, public Wi-Fi hot spots still compete with the cellular-based Internet services they have launched at a cost of billions. Compared with the improved efficiency that VoIP provides on wireline networks, there is little gain in terms of the bandwidth required to connect a wireless call.
That said, wireless VoIP could lighten the load on crowded cellular networks by allowing carriers to divert phone calls from their towers to Wi-Fi access points. According to a study by Kineto and IBM, connecting a call via Wi-Fi would cost an operator one-tenth of what it costs using a cellular network.
T-Mobile USA, a national wireless carrier with limited cellular capacity and the biggest investment in Wi-Fi, is widely known to be interested in melding its two networks.
Industry sources say the company, a member of the UMA consortium, might introduce a cellular/Wi-Fi phone by the start of 2006. It already is diverting some data traffic from its cell network, offering iPaq Internet users a switch to Wi-Fi whenever they are near a hot spot.
The United States could be one of wireless VoIP's first proving grounds because Wi-Fi's popularity here has led to a wide deployment of hot spots, providing a ready infrastructure for cellular handoffs.
The three largest U.S. carriers, Cingular Wireless, Verizon Wireless and Sprint, all have mused publicly about adding Wi-Fi and VoIP to their cellular mix.
Wireless VoIP also may enable cell phones to siphon more call traffic away from the traditional wireline business. That is an appealing prospect for all-wireless plays such as T-Mobile or Sprint, which plans to spin off its residential phone business as part of its merger with Nextel Communications.