Speedier phones still can't keep up with networks
- 04 May, 2010 04:42
Next-generation smartphones will be able to access the Internet at higher speeds, but costs and technical limitations will prevent them from getting the most out of the networks they are connected to.
Mobile phones generally connect to a cellular network for voice and data, but a growing number, especially smartphones, come with support for Wi-Fi, which generally offer faster speeds.
The number of smartphones that come with the 802.11n specification has started to accelerate, and by 2012 it will become the predominant Wi-Fi technology in handsets, according to ABI Research. For example, last week saw the introduction of the Nokia N8 and the Pearl 3G from Research In Motion. Thirteen smartphones have support for the finalized version of the 802.11n standard or the draft 2.0 version, according to the Wi-Fi Alliance's Web site.
The key to 802.11n's improved performance is MIMO (Multiple-Input Multiple-Output), a technology that uses multiple antennas in the access point and on the device to send data up to a theoretical 300M bps (bits per second). However, the N8, Samsung's Galaxy S and the Pearl 3G all lack support for MIMO, so a theoretical 300M bps drops to 75M bps, according to Samsung. The actual throughput is expected to be up to 35M bps, Samsung said via e-mail.
Another drawback with 802.11n on smartphones is that it will only work at 2.4GHz. The 5GHz-band has more channels available, which means more users can get higher speeds, according to Peter Jerhamre, systems engineer at Cisco Systems in Sweden. There is also much less interference at 5GHz -- performance in the 2.4GHz band can be affected by, for example, microwave ovens and Bluetooth, Jerhamre said.
For applications like wireless IP telephony, having the extra scalability and the cleaner airspace is important to ensure good performance, according to Jerhamre, who hopes phone vendors will add the 5GHz band to their 802.11n smartphones, as well.
Peter Thornycroft, applications manager at Wi-Fi infrastructure vendor Abuba Networks, agrees: the most significant improvement would be 5GHz operation, he said via e-mail. However, while this is important for enterprises, it would be less so for consumer networking, according to Thornycroft. He points out that there are a few smartphones from RIM, which is popular with business users, that work at 5GHz using the slower 802.11a standard.
There is of course an upside to skipping MIMO and not adding yet another frequency to the already long list today's smartphones come with. They can avoid issues with size, cost , complexity and power consumption that come from having more antennas, according to Thornycroft.
Still, 802.11n will offer significantly higher speeds than 802.11b and g, according to chip maker Qualcomm. Users will also get a better range and coverage, according to the Wi-Fi Alliance.
Wi-Fi isn't the only technology on next-generation smartphones that is getting a hobbled speed upgrade. Currently, the fastest 3G phones support a theoretical download speed of up to 10.2M bps using HSDPA (High-Speed Download Packet Access), compared to network and modem speeds of 21M bps. However, it seems like most upcoming smartphones that work with HSDPA will instead get 14.4M bps, rather than going up to 21M bps.
ST-Ericsson and Qualcomm are currently developing chipsets for the lower speed. Phone makers that Qualcomm listens to want 14.4M bps and therefore that is the path it will follow, the company said.
ST-Ericsson is also convinced that the highest-selling volumes will be at 14.4M bps, and that is what its smartphone platform, the U8500, is being developed for, according to Youssef Kamel , business director at ST-Ericsson's 3G Multimedia unit.
However, technical maturity also plays a part, Kamel said. For example, the algorithm used by HSPA+ at 21M bps needs more memory, and that adds to the overall cost, according to Kamel. However, smartphone vendors that really want higher connection speed can integrate ST-Ericsson's U8500 with the M570, a platform that is also used in USB dongles.
ST-Ericsson is talking to both smartphone and tablet makers about using a combination of those two products, but isn't ready to announce details such as release dates.. Smartphones based on just the U8500 will arrive by the end of the year, at the earliest, according to Kamel.
Huawei announced the first 14.4M bps smartphone at Mobile World Congress in February. The Android-based U8800 will become available during the third quarter, and is based on a chipset from Qualcomm. HTC and Samsung will likely be the first to follow Huawei, according to Carolina Milanesi, research director at Gartner.