Apple iPad 3 Wi-Fi Specifications

Update 15-March-2012 - As I mentioned, I'd have more information once iFixit performed their teardown of the new unit. Well they're doing it right now... Wi-Fi, Bluetooth, FM chipset - confirmed it's a Broadcom BCM4330. Sadly, it doesn't look like 40MHz support will be possible :(


So, Apple announced "the new iPad" yesterday (aka - the iPad 3). I've done some digging on it at the FCC for Wi-Fi specifications and here is what I've found out.

First, the new iPad models fall under the following FCC IDs:

• Wi-Fi Only FCC ID is BCGA1416
• Verizon LTE FCC ID is BCGA1403
• AT&T LTE FCC ID is BCGA1430

I'm only interested in the Wi-Fi specs, so I've looked up the Wi-Fi only model (A1416) at the FCC OET Equipment Authorization database. It's worth noting that much of the Bluetooth and Wi-Fi testing and certification was performed on the Verizon LTE model (A1403) and covers the other two models as well.

Wi-Fi and Bluetooth Capabilities

From the FCC test reports we can gather the following certification details:

• 1x1:1 MIMO (1 spatial stream)
• 20 MHz wide channels only
• 65 Mbps max raw data rate (likely)
• Bluetooth 4.0 including Low Energy mode and High Speed alternate MAC/PHY (leveraging the Wi-Fi chipset to offload large data transfer)

The combo Wi-Fi and Bluetooth chipset used by the iPad 3 is definitely NOT the same Broadcom chip used in the iPad 2 and iPhone 4 (which used the Broadcom BCM43291HKUBC). We won't know for sure what chipset is being used because the FCC internal photos are currently marked "Confidential" until 05-Aug-2012. However, once iPad 3 devices start shipping on 16-Mar there should be an iFixit teardown to give us insight.

My guess is that there are significant hardware improvements under the hood, which Apple may not be leveraging at time of initial release but may drop an update later on down the road. We know for sure from the FCC test reports that it support Bluetooth 4.0, which should be a major improvement over 2.1 + EDR found in the iPad 2. If Apple is using another Broadcom combo chip, which is highly likely, it could be the BCM4334 which is designed for smartphones and tablets. Broadcom product literature even includes very "Apple-esque" verbiage around highly mobile devices and push-email. This would be an intriguing choice since that chip offers single-stream 802.11n, dual-band operation, and 40MHz wide channels. Broadcom also lists concurrent dual-band capability for Wi-Fi client access on one band while simultaneously using Wi-Fi Direct or Wireless Display on the other band using what they call "advanced switching techniques."

If Apple does drop a software update at a later date for the iPad 3, we could see Wi-Fi specs bumped to:

• 1x1:1 MIMO (1 spatial stream)
• 40 MHz wide channels
• Short Guard Interval (SGI) support
• 150 Mbps max raw data rate

However, this may or may not happen. Support for 40 MHz channels would be a nice upgrade to enhance the product as it ages and keep it relevant. But it could have significant battery life implications which may make Apple hesitant to adopt. Also, SGI support is possible but unlikely since the chipsets used in the iPad 1 and iPad 2 were similarly capable but was not implemented by Apple (as Keith Parsons did an excellent job of analyzing on his blog).

iPad 3 Supported
Frequency Bands

Frequency Bands Supported

Note - All frequency ranges reference center channel frequencies from low to high channel.

Bluetooth:

ISM (2402 - 2480 MHz) - Bluetooth Frequency Hopping (FHSS)

ISM (2402 - 2480 MHz) - Bluetooth 4.0 Low Energy (BT LE)

Wi-Fi:

ISM (2412 - 2462 MHz)

ISM (5745 - 5825 MHz)

UNII-1 (5180 - 5240 MHz)

UNII-2 (5260 - 5320 MHz)

UNII-2 Extended (5500 - 5700 MHz)

UNII-3 (5745 - 5805 MHz)

The good news here is that the iPad will support operation using 20 of 23 available UNII channels. This should help enterprise network administrators plan for infrastructure deployments that can utilize the UNII-2 Extended frequency band. The 3 channels that are disabled (ch 120-128) in the 5600 - 5650 MHz range are disallowed for operation in the U.S. by the FCC DFS regulations due to Terminal Doppler Weather Radar (TDWR) systems.

Administrators have been reluctant to enable use of these channels in their networks because few clients have supported it. Enabling it on the APs would therefore result in "black holes" where clients would not be able to connect to the network. However, as more clients support this band administrators should look to verify client compatibility across the range of devices they support and, if possible, enable use of this band for greater Wi-Fi network capacity to meet the growing need for high-density deployments.

Additionally, channel 165 (ISM 5825 MHz) is available for use in the new iPad 3. However, few if any network administrators typically enable support for this channel in their deployments.

Antenna Gain

Here you can see the internal antenna gain in the iPad 3:

iPad 3 Integrated Wi-Fi Antennas

Power Output

Power output varies based on the exact frequency of transmission or channel of operation due to FCC regulations that limit spurious side-band emissions. Therefore, power output is usually lower on frequencies at the lower and upper edges of the bands. For simplicity, I will provide the range of power output values reported by the FCC across each band. For detailed information, see the FCC test reports.

Bluetooth

FHSS - 10.80 to 11.90 dBm

Bluetooth 4.0 Low Energy - 8.70 - 8.90 dBm

Wi-Fi

The Wi-Fi values get even more complicated because of the variations in spectral masks used by different 802.11 physical layer technologies. I've summarized the FCC test results into the following table for easier reference.

iPad 3 Wi-Fi Output Power (Average)

FCC Regulations Update

It appears that in May 2011, the FCC adopted new requirements for client device operation in the UNII-2 and UNII-2 Extended bands with regards to radar detection capabilities (or lack thereof). It reads:

Devices to be approved as UNII clients need to show compliance with the general requirements of Section 15.202, in addition to the technical requirements of Part 15E.  According to the requirements of Section 15.202, a client device must rely on a master device to initiate a network if the client device does not have radar detection capability.  Such a client device cannot initiate, or be configured to initiate, any transmissions including transmissions from probes, beacons or support ad-hoc modes of operation.  The operation of a device as a Group Owner for Wi-Fi Direct in the bands is therefore limited only where it is approved as a master according to the requirements of Section 15.202 (see KDB # 594280).

So, a client device can avoid implementing radar detection as long as the manufacturer certifies that it will not operate in ad-hoc or peer-to-peer mode. The device must only perform passive scanning to find a "master device" (e.g. an access point) that is capable of radar detection and is already operating on the frequency. In addition, this also applies to Wi-Fi Direct operation by the device.

Apple and other device manufacturers are now required to submit a DFS Attestation, similar to the following: 

Apple iPad 3 (A1416) DFS Attestation Letter

Conclusion
Although at first glance the iPad 3 appears to be similarly capable as the iPad 2, the underlying hardware could be much more powerful. Whether or not Apple decides to release a software update to unleash greater Wi-Fi transfer speeds at a later date is unknown, but could form the basis for a strategy to keep the iPad 3 unit relevant as a low-end option once the next version of the iPad is released, likely supporting 802.11ac for even greater speeds.

Additionally, the support for DFS channels in both the UNII-2 and UNII-2 Extended bands is a great sign for Wi-Fi networks to enable greater capacity.

Cheers,
Andrew vonNagy