
IPhone 4 3G Data Performance - gthank
http://daringfireball.net/2010/07/iphone_4_3g_performance
======
cscotta
The speeds we're starting to see on next-gen mobile devices + networks are
pretty impressive - more than can be used effectively without draining the
battery in a hot second, at least. Now that we've got bandwidth figured out,
it's time to tackle latency.

A coworker ran a speed test on his AT&T iPhone 4 in NE Portland at lunch and
got about 1.4mbps down with a 150ms ping. I get about 3.9 - 4.3mbps down with
an 80ms ping with my Nexus One (T-Mobile): <http://j.mp/94sfpF>

Both of these speeds are fantastic. The bandwidth question is highly network-
dependent, and almost entirely moot once you're beyond the 800k mark --
especially with a low-latency ping, which is likely the biggest bottleneck
when browsing the web.

We need device manufacturers and carriers to work closely, striving to reduce
latency in mobile connections. For developers, it's critical to drive home the
point of minimizing the number of HTTP requests. If you've got a minimum 200ms
round-trip for each call and 98 items to load (NYT.com, tested a moment ago),
it adds up quickly.

~~~
jazzychad
Amen to that. I wrote a test app which downloads a single image from the net.
There is a progress bar so you can actually see how "quickly" the bytes come
in. I kick off the request, and the majority of the time is spent waiting for
the first byte. I was pretty surprised by this. All this time I was thinking
it was the throughput that was slow; but no, the latency really is the killer
here.

~~~
spudlyo
Bad latency makes for a terrible interactive terminal experience too. I
remember SSH on my first gen iPhone was awful.

~~~
Prisen
Improved latency is one of the major improvements that 4G (lte) has over 3G.
Networks are already being rolled out, it won't take long until there is
coverage in major cities.

------
ZeroGravitas
The more you learn about the iPhone 4 the suckier the iPad first generation
seems. You would have assumed that it was _at least_ the iPhone 4 with a
bigger screen, but they must have been really trying to hit a price point.

~~~
jsz0
Maybe so. The $499 starting price for the iPad is a very important part of its
success. Another possibility is the iPad was in the pipeline before the iPhone
4 was designed and it was simply too late to re-design the antenna and
integrate a new radio chipset. If you're working with a 12 month release cycle
a delay of an additional 3 or 4 months is unacceptable. At some point they had
to commit to shipping something

------
KirinDave
Something else I am not the first to notice: the "magic spot" problem doesn't
affect Edge.

It really makes me wonder if there is an underlying software or firmware issue
that is exacerbating the problem. The fact that upload isn't significantly
impacted, nor Edge, suggests some sort of phone freakout that's not strictly
dictated by the hardware to me.

~~~
mechanical_fish
The "magic spot" "problem" does not affect the Edge band _for this particular
user, in this particular location, on this particular day, in this particular
phase of the moon_.

Antenna design is black magic on the best of days. When you mix in all the
variables at play across three million phone users around the country you get
lots of irreproducible results.

What I find myself wondering is: Sure, closely coupling a big bag of saltwater
(e.g. me) to the phone may [1] tend to reduce the antenna efficiency relative
to leaving the phone alone on a table. But can I strap the iPhone into some
sort of specially-designed case that's designed to _increase_ the antenna
efficiency?

[1] EDIT: This word used to be "will", but having just read Anandtech's fun
analysis of this "problem", I am reminded that what giveth in one waveband
taketh away in another: Anand _improved_ his WiFi signal power under certain
conditions by gripping the phone.

~~~
KirinDave
That is a very optimistic idea.

I wouldn't have mentioned the edge thing except that I've heard that sentiment
repeated a lot, and I've asked other people for confirmation.

