Sixteen things you should know about iPhone MMS & Tethering

Although iPhone OS 3.0 introduced MMS and tethering capabilities to the iPhone, support for these features has not yet been made available on all carriers in all countries. Notably, Apple’s original iPhone partner, AT&T was one of the few iPhone carriers in the world to not provide MMS support at the time of the iPhone 3.0 launch, and remains one of the few major carriers not providing any kind of tethering support.

Note that you can find a list of the various iPhone carriers around the world and which features they provide in Apple’s Support Knowledgebase article, Locating iPhone Wireless Carriers

With AT&T finally beginning their rollout of MMS support, we hope that tethering will not be too far behind. To this end, we offer some tips and insights for our readers on what to expect from these features and how to get the most out of them.

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MMS, short for Multimedia Messaging Service is an expansion of the SMS text messaging service to allow multimedia content such as pictures, video clips and audio to be sent over the cellular network between compatible devices. Although the iPhone itself provides a number of methods such as e-mail support for sending content, the advantage of MMS is that messages can be sent to many other non-smartphone devices—phones that may not even be capable of receiving e-mail or accessing the Internet.

1. MMS is an extension of the normal Messages app

You won’t see a separate MMS app. The existing Messages app is also used to send MMS messages once the feature is enabled. The quickest way to determine if MMS is supported is to look for the little camera button to the left of the text entry field. This button is used to browse your photo library to send pictures and videos via MMS.


2. A carrier settings update is required to enable MMS

The iPhone hides all MMS-related features unless MMS has actually been enabled in the carrier settings file. These files are specific to each carrier, and the MMS settings are not enabled for carriers that don’t support that feature. This means that when a carrier adds support for MMS they must also send out an update to their carrier settings file. These updates are distributed through iTunes, so you will need to connect your iPhone to iTunes in order to receive the updated carrier settings.


iTunes checks for carrier updates for the iPhone in the same way that it checks for firmware updates. If the carrier settings update is not detected automatically, you can force iTunes to check for it by clicking the “Check for Updates” button on the iPhone Summary screen in iTunes. Note that since the carrier settings update process is the same as the iPhone OS update process, you will also need to have already downloaded and installed the latest iPhone OS update, otherwise you will be prompted to install that first before receiving the carrier update.


Also keep in mind that once MMS is enabled by your carrier, MMS support can be toggled on or off in the iPhone Settings app, under Messages. If you’ve received the carrier update and still aren’t seeing MMS options appear, be sure to check these settings.


You can confirm that you have the actual carrier update installed on your iPhone by going into your Settings app and choosing General, About. The “Carrier” information will show the version of the carrier settings file that is in use. For the AT&T MMS carrier update, it should read “AT&T 5.5”


3. The original iPhone will not support MMS

Unfortunately, users who are still toting the original first-generation iPhone will be left out of the MMS club. The exact reasons for this limitation are unclear, but the bottom line is that MMS support requires an iPhone 3G or iPhone 3GS, and there’s no reason to expect that Apple is ever going to introduce this capability to the original iPhone.

4. Sending video is still limited to the iPhone 3GS

Even though iPhone OS 3.1 provides the ability to store video files in your photo library on all iPhone and iPod touch models, the ability to actually send video files out via MMS is still restricted to the iPhone 3GS. If you’re using an iPhone 3G, you’ll find that the “Sharing” button that normally appears in the bottom-left corner for photos is conspicuously absent when viewing videos, and videos are simply omitted when browsing the photo library from the Messages application.

5. MMS is not just for pictures and video

Although photos and videos are the primary content of MMS for most users, the MMS specification actually supports just about any file type. On the iPhone, you can also send voice memos and contact information via MMS by tapping the sharing button in the respective application.


6. MMS messages will scale down content

MMS was not designed with the intention of transmitting large files over the cellular network. Further, many of the cell phones which support MMS have much lower-resolution screens and lower memory capacity than the iPhone. As a result of both of these factors, the content you send via MMS may need to be resized and trimmed to fit within these constraints.

Specifically, expect photos to be resized to a maximum resolution of 1024 x 768 and videos to be scaled down to 176 x 144 with a frame rate of 10fps and an 8khz audio track.


Further, longer videos and audio recordings may need to be trimmed prior to sending. The iPhone will notify you if this is the case and give you an opportunity to trim the video or audio-clip on-the-fly. The maximum length of an audio or video clip to be sent over MMS appears to be approximately one minute.


7. You can send MMS messages to e-mail recipients

Sending of MMS messages is not limited only to phone numbers. Once MMS is enabled, you can enter an e-mail address in the TO: field to send an MMS message to an e-mail recipient.


On most carrier networks, the recipient will receive an e-mail with a web link to view the received MMS content.

Since the iPhone includes a built-in e-mail client, and MMS content is significantly scaled down when compared to e-mail attachments, we can’t see too many reasons to use this capability, but it’s there nonetheless.

8. You can send MMS messages to non-MMS users

If you’re sending an MMS message to a phone or subscriber that does not support MMS, the recipient will simply receive an SMS message with a web link to view the received MMS content, similar to how sending an MMS via e-mail works.

9. Check your plan

Different carriers bill for MMS messages differently. Some carriers simply count MMS messages as text messages and include them in your text messaging plan, while other carriers charge for MMS messages separately and may offer MMS-specific plans and packages. Further, many carriers will happily allow you to send MMS messages even if you’re not subscribed to the appropriate plan and just bill you a per-message charge for any MMS messages you send or receive.

The bottom line is that you shouldn’t assume that MMS messages will be included in your text messaging plan. Be sure to check with your carrier to confirm how they handle billing for MMS messages and whether you need to add any additional plans or features for MMS support.

Note also that if your carrier charges separately for received MMS messages and you don’t wish to subscribe to an MMS plan, then you may wish to disable MMS support entirely by going into Settings, Messages on the iPhone and toggling MMS messaging off. Depending on your carrier, disabling MMS will result either in received MMS messages being ignored entirely or being received instead as text messages with a link to a web page where the MMS content may be viewed.


iPhone OS 3.0 also introduced the ability to use your iPhone as a wireless “modem” to access the Internet from a computer. While AT&T has yet to introduce support for tethering, carriers in several other countries, including Canada and most of Europe have already been providing tethering support for some time. Here are some things to keep in mind if you’re interested in setting up tethering.

10. The original iPhone does not support tethering

As with MMS, the original first-generation iPhone does not provide tethering support either. Since the original iPhone is limited to GPRS/EDGE network speeds, tethering performance would likely be so slow on the original iPhone as to be a source of frustration for many users.

11. Enabling Tethering

As with MMS, a carrier settings update is required to enable tethering from your provider. Tethering options will not appear unless they have been enabled by your carrier. Note that unlike MMS, tethering is disabled by default on your iPhone, and you will need to turn it on if you plan to use it. This is done from the Settings app, under General, Network, Internet Tethering. The option will appear here either as “Set Up Internet Tethering” or simply an option to access the tethering settings and switch tethering on or off.


Note that when enabling tethering, the iPhone may check with your carrier to see if you have a tethering package. In this case you may need to contact your carrier to have your account provisioned for tethering.


12. You’ll need iTunes for USB tethering

If you’re tethering via USB, you will need to have iTunes 8.2 or later installed on any computers that you want to tether from, as the Windows or Mac OS X drivers for tethering are included in the iTunes installation. With iTunes installed and tethering enabled on your iPhone, it should appear as an Ethernet network device and immediately go into tethering mode as soon as you connect it to your USB port.

13. Bluetooth tethering

Tethering over Bluetooth does not require iTunes. Instead, the iPhone uses the standard Bluetooth Personal Area Network (PAN) profile. This requires that your computer hardware use at least Bluetooth v2.0 and support the PAN profile. All recent Mac computers provide PAN support, as should most recent mainstream Windows computers, although actual Bluetooth capabilities may vary widely with the wide diversity of Windows configurations available.

14. Check your plan before tethering

As with MMS, tethering may or may not require subscription to a separate tethering plan, and may or may not be billed separately from normal iPhone data usage. As out-of-plan data usage can get frighteningly expensive, be sure to check with your carrier as to their tethering policies before enabling and using tethering.

AT&T’s plans for tethering in the U.S. are not entirely clear as they have not as of yet announced the availability of tethering support. In Canada, Rogers and Fido are currently providing tethering data usage included in any iPhone data plan over 1GB per month until the end of 2009, at which point they may begin charging separately for it. In the UK, O2 requires that you add a tethering “bolt-on” package for an additional cost.

15. Keeping track of your tethering usage

If you’re using iPhone OS 3.0, you should note that your tethering data usage may not be included in your normal data usage screen, particularly if you’re with a carrier which tracks tethering usage separately from normal iPhone data usage. In this case, the “Cellular Data Usage” only includes data usage from the iPhone itself, and not data used while tethering.

iPhone OS 3.1 adds an additional section below the normal data usage summary to track your tethering usage separately.


Sixteen things you should know about iPhone MMS & Tethering

16. Your tethering speeds may vary

Your maximum Internet connection speed while tethering depends on a number of factors. The most obvious of these is your carrier’s 3G network speed in your area, which can range from 1.8 mbps through to 7.2 mbps or even higher. Most AT&T areas are limited to 3.6 mbps, although AT&T has begun rolling out 7.2 mbps service in some areas. In Canada, Rogers and Fido provide 7.2 mbps speeds on most of their 3G network.

The next consideration is your iPhone model. The iPhone 3G provides a maximum 3G throughput of 3.6 mbps, while the iPhone 3GS provides a 7.2 mbps maximum.

Whether you are using a USB or Bluetooth connection for tethering will also make a difference. USB is significantly faster than even the fastest 3G network speeds, whereas even the fastest Bluetooth implementation is limited to 2.1 mbps.

Of course keep in mind that all of these are maximum speeds, and real-world usage scenarios may result in significantly lower speeds based on network congestion and other factors. Time of day can also make a noticeable difference, since network speeds are affected by the number of users who are currently using the network.

Since the same 3G hardware in the iPhone is used both for internal data and tethering data, you can get an estimate of what kind of performance you can expect from tethering simply by downloading an iPhone app such as (iTunes link) and running a test over your 3G connection.


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