Next-gen iPod touch, iPhone to support low-power 802.11n
Wireless radio component specifications contained within beta distributions of iPhone 3.0 firmware reveal support for a new chip enabling low power 802.11n that's bound for Apple's third-generation iPod touch. It's therefore also likely to be included with new iPhone models.
The version of the existing Broadcom chip that supplies WiFi and Bluetooth on existing models jumps from BCM4325 to BCM4329, according to resource files reserved for a third-generation iPod touch. The component upgrade adds new support for 802.11n features, including the ability to find and join 5GHz networks.
Existing iPhone and iPod touch models only support 5GHz 802.11a networks, or 2.4GHz 802.11b/g networks, forcing users who want the top speed of 802.11n (available on all MacBooks) but compatibility with 802.11b/g networks (to use the existing iPhone) to set up a 2.4GHz compatible network. That compromise forces the wireless network to deal with interference from other networks on the often crowded 2.4GHz band.
Apple's latest generation of AirPort base stations added new hardware support for dual-band networks, allowing both fast and slow devices to connect to independent 5GHz and 2.4GHz signals at the same time. However, this isn't possible with previous AirPort base station hardware, or when setting up an ad-hoc WiFi network from a notebook, for example.
New support for 802.11n in the upcoming iPhone and iPod touch models would also provide the devices with additional network speed and reception range features of the significantly faster 802.11n specification, which are related to channel bonding (using two channels at once to double the top reception speed) and MIMO, the ability to use multiple transmit and receive antennas to improve reception speed and range.
Other features related to 802.11n include Space Time Block Coding (STBC), which sends the same data across multiple antennas for redundancy against radio interference; Short Guard Interval (SGI), which increases the data rate by squeezing out shorter padding intervals; A-MPDU, the aggregation of multiple MAC-level service data units; Block Ack, which increases efficiency by transmitting multiple data frames followed by only one acknowledgement frame in a transmission block; Greenfield mode, the increased efficiency gained by dropping 802.11a/b/g backward compatibility; and RIFS, reduced interframe spacing, which minimizes unused radio dead time by cutting the interval time between sent packets.
The new device also focuses on efficient power management, with a special integrated PMU (power management unit) and a shared Bluetooth and WiFi receive signal path, which "eliminates the need for an external power splitter while maintaining excellent sensitivity for both Bluetooth and WLAN."
The new component should dramatically speed up WiFi throughput and flexibility as AT&T and other UMTS mobile providers also upgrade their 3G networks to take advantage of parallel improvements in mobile 3G speed capacity expected in the new iPhone.
The version of the existing Broadcom chip that supplies WiFi and Bluetooth on existing models jumps from BCM4325 to BCM4329, according to resource files reserved for a third-generation iPod touch. The component upgrade adds new support for 802.11n features, including the ability to find and join 5GHz networks.
Existing iPhone and iPod touch models only support 5GHz 802.11a networks, or 2.4GHz 802.11b/g networks, forcing users who want the top speed of 802.11n (available on all MacBooks) but compatibility with 802.11b/g networks (to use the existing iPhone) to set up a 2.4GHz compatible network. That compromise forces the wireless network to deal with interference from other networks on the often crowded 2.4GHz band.
Apple's latest generation of AirPort base stations added new hardware support for dual-band networks, allowing both fast and slow devices to connect to independent 5GHz and 2.4GHz signals at the same time. However, this isn't possible with previous AirPort base station hardware, or when setting up an ad-hoc WiFi network from a notebook, for example.
New support for 802.11n in the upcoming iPhone and iPod touch models would also provide the devices with additional network speed and reception range features of the significantly faster 802.11n specification, which are related to channel bonding (using two channels at once to double the top reception speed) and MIMO, the ability to use multiple transmit and receive antennas to improve reception speed and range.
Other features related to 802.11n include Space Time Block Coding (STBC), which sends the same data across multiple antennas for redundancy against radio interference; Short Guard Interval (SGI), which increases the data rate by squeezing out shorter padding intervals; A-MPDU, the aggregation of multiple MAC-level service data units; Block Ack, which increases efficiency by transmitting multiple data frames followed by only one acknowledgement frame in a transmission block; Greenfield mode, the increased efficiency gained by dropping 802.11a/b/g backward compatibility; and RIFS, reduced interframe spacing, which minimizes unused radio dead time by cutting the interval time between sent packets.
The new device also focuses on efficient power management, with a special integrated PMU (power management unit) and a shared Bluetooth and WiFi receive signal path, which "eliminates the need for an external power splitter while maintaining excellent sensitivity for both Bluetooth and WLAN."
The new component should dramatically speed up WiFi throughput and flexibility as AT&T and other UMTS mobile providers also upgrade their 3G networks to take advantage of parallel improvements in mobile 3G speed capacity expected in the new iPhone.
Comments
The lowest common denominator aspect of wireless networking is quite inconvenient, as the chances of all the devices in any given environment having the latest wireless spec are close to nil.
Existing iPhone and iPod touch models only support 5GHz 802.11a networks, or 2.4GHz 802.11b/g networks
Huh? I'm only seeing support for b/g networks, not a:
http://www.apple.com/iphone/specs.html
http://www.apple.com/ipodtouch/specs.html
I would love to see the next generations work on the 5Ghz band, since that's all I run now to keep out of the b/g noise from my neighbors.
Huh? I'm only seeing support for b/g networks, not a:
http://www.apple.com/iphone/specs.html
http://www.apple.com/ipodtouch/specs.html
I would love to see the next generations work on the 5Ghz band, since that's all I run now to keep out of the b/g noise from my neighbors.
I didn't know the chips supported 802.11a, but it wouldn't surprise me as Macs were capable of 802.11a/b/g networks for a couple years but never listed it on their site. Obviously they didn't want to officially support the standard, but as to exactly why I don't know.
Dave
The article doesn't mention, but the screenshot text refers to FM receive and transmit. This could be interesting -- particularly to Belkin, Griffin, et al. who still have a large business in FM connectivity for iPod playback in autos. Plus, when I travel, it's always fun to listen to a little local broadcast radio -- on the fly. I wonder if iPhone OS 3.0 will support the FM H/W capability of the Broadcom chip?
That is refering to the frequency modulation of the radios for the 802.11 radios. If Apple hasn't supported a typical FM radio feature at this point in the game I think it's safe to say that they never will.
Even if it just means that you won't bring down the speed of your "n" network anymore by forcing it to "g", it's worth it. Not everyone's running out replacing their TimeCapsules and AirPort Extreme Base Stations just for the one new feature. Right now, my iPhone is the only device bogging down my network speed.
Keeping your 'n' network from downgrading to the "weakest link" or going from 5GHz to the interference heavy 2.4GHz frequency is great, I just hope that even the low power 'n' uses the same power as 'g'. Regardless, even if the speed is the same as 'g' it is a major plus for the reasons you mention.
Is 802.11n an official spec yet?
I think it's due to be approved sometime in Q3 2086, at this rate.
Even if it just means that you won't bring down the speed of your "n" network anymore by forcing it to "g", it's worth it. Not everyone's running out replacing their TimeCapsules and AirPort Extreme Base Stations just for the one new feature. Right now, my iPhone is the only device bogging down my network speed.
I replaced mine... just for fun really, but now the PS3 and MacBook play nicer with each other. I use an Express to beam across to my workplace (across the street). Nothing earth shattering, but apple's extender functions are the easiest I've seen.
I'm all for low-power, more speed... yada yada.. but just how fast does a device with a 3 inch screen really need to be? I mean, can't they shrink pr0n so it doesn't take so much bandwidth? What else are people doing with these millions of gigglebytes?
A couple of applications will consume more bandwidth in the future:
- video (both download and upload, if the rumors of an iPhone video camera turn out to be true)
- web pages (remember that the browser on the iPhone has to deal with the actual Internet and all its bloated content, not just some mobile-tweaked pages)
- possible multi-user games
- Ron Jeremy's Hi-Def Virtual Back Shaving Party (those individual hairs take a lot of bytes to render)
- Lots and lots of non-stop twitter use for the terminally vacant
That is refering to the frequency modulation of the radios for the 802.11 radios. If Apple hasn't supported a typical FM radio feature at this point in the game I think it's safe to say that they never will.
Solipsism, I think Futurist has a valid observation - reading up on the chip on Broadcom's website indicates that the FM transmitter/receiver on this chip is just as he suspects - to broadcast audio on FM Radio, or to receive FM Radio broadcasts. And as he also points out, Apple may or may not decide to implement this feature, but the hardware is capable.
Also, reading on the current chip used (BCM4325), it is capable of only receiving FM radio signals - a feature that has not been implemented in software.
Solipsism, I think Futurist has a valid observation - reading up on the chip on Broadcom's website indicates that the FM transmitter/receiver on this chip is just as he suspects - to broadcast audio on FM Radio, or to receive FM Radio broadcasts. And as he also points out, Apple may or may not decide to implement this feature, but the hardware is capable.
Also, reading on the current chip used (BCM4325), it is capable of only receiving FM radio signals - a feature that has not been implemented in software.
Upon further reading, I think he does too. There are aspects to chips that Apple has never used, like VC-1 decoding on the chip, so it is possible.
A couple of applications will consume more bandwidth in the future:
- Ron Jeremy's Hi-Def Virtual Back Shaving Party (those individual hairs take a lot of bytes to render)
- Lots and lots of non-stop twitter use for the terminally vacant
As long as it's not a video of Ron shaving himself, but of him shaving some pretty lass, I would see it!
another thing I'm hoping for in the 3rd gen Touch is a change in the metal on the back. I find the current shiny back is rather slippery and shows fingerprints. I'd really welcome an anodized matte black finish to solve those issues and I think it would look awesome.