Push vs Fetch in terms of Data and Battery Usage

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Level 1

8 points

Push vs Fetch in terms of Data and Battery Usage

Which use more?

I'm thinking about getting a data plan for international travel and, instead of having people from home call my phone at 1$ to 2$ a minute, they should contact me via email.

I have an email account I could use that currently gets no other activity/mail. I was thinking if I set this account up as a "push" account, I could get and respond on a near real-time basis... kinda like a text phone.

My question is, is "push" merely a constantly running fetch process (heavily using data and battery), or does it act like it sounds - phone in pure standby (no data usage, low battery usage) and the responsibility is on the network to send data only when there is an email to actually "push."

MBP 2.16, Mac OS X (10.4.8)

Posted on Jan 17, 2010 5:26 PM

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Answer 1

Top-ranking reply

Allan Sampson

Level 10

123,683 points

Jan 17, 2010 7:05 PM in response to reppans

When adding/creating an email account, the following presets are available.

Exchange
MobileMe
Gmail
Yahoo Mail
AOL

If you selected the Yahoo Mail account preset when adding/creating the account, the account was created as an IMAP account with Push access available for received messages along with an option to enable or disable Push access for the account.

The data required to connect with the incoming mail server for an email account to check the incoming mail server for new messages is minute. More battery will be used the more often an account is checked for new messages, but this alone is not a significant battery drain and especially with a single email account. All server stored mailboxes with an IMAP account are not synchronized with the server when the account is checked for new messages. For example, the account's server stored Sent mailbox is not synchronized with the server until the account's Sent mailbox is selected.

Push is not a constant fetch process. With an account that supports Push access for received messages, a new message received at the incoming mail server is "pushed" to the iPhone without the account having to be checked for new messages. In theory, Push access should use less battery compared to automatically checking the account for new messages, which isn't always the case and this also depends on the time interval set for automatically checking for new messages. You can have the account automatically checked for new messages every hour.

Depending on how much data is accessed compared to the number and length of phone calls when roaming internationally, data access can be much more expensive.

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Answer 2

Jan 17, 2010 5:43 PM in response to reppans

You can't enable Push access for any email account with the iPhone's Mail application.

Push access with the iPhone's Mail client is supported with a MobileMe account, with a Yahoo account that is created using the Yahoo account preset, and with an Exchange account with ActiveSync enabled for the account at the Exchange Server for the account.

In theory, Push access should use less battery but data access will be the same. With Push access, new messages received at the incoming mail server server are "pushed" to the iPhone by the incoming mail server without having to automatically or manually check the account for new messages, but data downloaded will be the same.

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Answer 3

MobileDev

Level 3

565 points

Jan 17, 2010 8:12 PM in response to reppans

Yes, "push" is actually a type of fetch.

Your device sends a message to the mail server and then waits for X amount of time for a reply. If/when the server gets mail, it sends the reply instantly down the same path.

Now, the catch: the X amount of time the device can wait for a reply is dependent on how long the entire path stays open between you and the server.

For example, if even one network device times out your connection in ten minutes, that's how often your device must talk to the server to keep the connection going, and your battery life will suffer accordingly. (If you're lucky, the delay can be much longer, up to say forty minutes.)

So your device is going to be sending a short message to the server every 5 - 45 minutes all day and night.

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Answer 4

Jan 17, 2010 7:06 PM in response to reppans

I would make very sure that your international data plan covers so much data usage. You'd be surprised how much data a push email account will use, and if you have overages overseas you're gonna hurt on the billing end of things.

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Answer 5

reppans Author

Level 1

8 points

Jan 17, 2010 8:26 PM in response to crawfish963

The international plan is 20mb for 25$ for a month.... I typically use 100-150mb per month, but given a trip might only be a week in that month, and I could cut the mindless internet surfing to wifi locations, I think I could live with 20mb easy for email only.

You can also see your exact usage on the Settings>General>Usage statistics and always call in to upgrade the plan if you see yourself heading over the limits.

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Answer 6

reppans Author

Level 1

8 points

Jan 17, 2010 6:33 PM in response to Allan Sampson

My normal email is a MobileMe acct and the unused email is a yahoo acct, although it is old, and I don't recall setting it up with a "preset", I'll have to figure out how to get that working for push.

But let's just say I use the MobileMe acct. I understood that fetching will use data (and battery) with each negotiation/synch/check process, even if there are no new emails. Was wondering if push avoided that. Also, reading many battery life threads, everyone says to turn push off, so I'm wondering if push isn't really just a constant fetch process?

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Answer 7

reppans Author

Level 1

8 points

Jan 17, 2010 8:13 PM in response to Allan Sampson

Then my Yahoo account is set-up for push.... I used an iPhone preset when I first set-up the mail accounts on the phone, and I do get the options to push/fetch/etc for the account in the general settings. I have not yet used push on either account yet though, as battery life is has always been a higher priority than timely emails for me. Just briefly tried push between the 2 email accounts on my phone (one push, the other not) and I could not get it to work properly, perhaps because both accounts are on the same phone. Will try later from laptop to the phone.

If it is a true server "push," then if I do use this inactive Yahoo account as my international "telephone" line, and no emails (calls) come through on a given day, then I assume I will use no international data roaming or incremental battery. Still wonder why everyone suggests turning "push" off as a solution to the short battery life threads, though.

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Answer 8

reppans Author

Level 1

8 points

Jan 17, 2010 8:35 PM in response to MobileDev

Now I'm confused....

Getting somewhat conflicting responses here.... is this a definitional thing?

If we equate it to voice communication, the phone is constantly communication back and forth to the cell network, eating batteries, but we don't get charged until a call is actually "pushed" to us. Can the same be said for "push" email? I'm reasonably certain an automated fetch will generate data roaming charges, even if there are no emails.

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