communicating in wales: design and architecture for mobile applications over poor connectivity
TRANSCRIPT
Communicating in Wales: design and architecture for mobile applications over poor connectivity
Alan Dix
http://alanwalks.wales/
Tiree
Tiree Tech Wave26-30 Oct 2017
University ofBirmingham
today I am not talking about …
• physicality and product design
• long tail of small data
• community technology
• intelligent internet interfaces
• digital humanities
• creativity and Bad Ideas
• visualisation and sampling
• situated displays
• virtual crackers and slow time
• modelling dreams and regret
• the emergence of self
not to mention …
REF
I am talking about …
connectivity
… or the lack of it!
poor connectivity
three aspects:
• user experience
• architecture and infrastructure
• policy
… but first a little about a walk
walking Wales
1058 miles (1700 km) around around the margins of Wales
Welsh Coast Path
opened May 2012
linking existing paths
a single way marked route
with Offa’s Dyke encircles Wales
three full traversals in 2012 (one running)
vision
personal
encircling, encompassing, pilgrimage, homecoming,
practical
IT for the walker & IT for local communities
philosophical
reflections on walking and space, locality and identity
research
personal agenda and living lab
no hard boundaries
research – practicepersonal – philosophical
19th century science or Mediaeval?
walking Wales
technology
me: “what technology do you use?”walker: “a map”
the best technology!
voice recorder
real buttons!!
use it while moving
while walkingactive
camera, recorderpassive
GPS, ECG, EDA
when stoppediPad, blog, flickr,
social media,uploading data
before/afterweb for planningnew contacts on
Twitter, emailreporting, analysis
while walkingother walkers
occasional friends/family
meeting
when stoppedshop keepers,
B&B proprietors,chance meetings
talks, visits
before/afterfamily and friends,
readers, researchers,
future walkers
socialsphere
technicalsphere
data
location
GPX ... batteries ... sporadic signals ....
bio-sensing
ECG (heart), EDA (skin) and accelerometers
audio and images
in the moment
text
after the event
implicit
explicit
user experienceconnectivity problems
I expected it to be bad ...
but it was worse
... not a recent issue ...
not just jerky movies ...
Software Update 2.3Gbsecurity patch
software makes it worse ...
Twitter 140 chars ...
but unusable with poor signal
email slow but works – 1970s technology
Flickr uploader freezes on poor connections
... even in Paris!
✔
✗
✗
user experienceprinciples
time matters
timescales
ms secs mins hours days
local interaction + syncronisation
store & forward
hand-eyecoordination
split-feedbacksyntactic/semantic
local feedbackpre-compute
requestresponse session
vocabulary … just words?
bandwidth … how much
delay … how long
jitter … how variable
glitches
frequency
length of drop
ms secs mins hours days
ms
secs
mins
hours
days
totalfailure
jitter
intermittentconnectivity
glitches
principles
store and forward… in an age of instant
restarting after problems
connectivity-aware applications also cost, energy, etc. e.g. rich media
architecture& infrastructure
the bits leak out
recall …software makes it worse ...
Twitter 140 chars ...
but unusable with poor signal
Flickr uploader freezes on poor connections
... even in Paris!
N.B. both as in 2013
Twitter experience
Twitter – why?
code (on start)
– read news-stream
– build UI
– allow tweets
https://dev.twitter.com/rest/reference/get/statuses/home_timeline
https://dev.twitter.com/rest/reference/get/statuses/home_timeline
5 pages later …
$ wc one-tweet.json
163 304 4468
https://dev.twitter.com/rest/reference/get/statuses/home_timeline
Twitter – why?
code (on start)
– read news-stream
– build UI
– allow tweets
could be
– asynchronous load
– lightweight version of API
140 chars = 5-10K in JSON/XML API
50 items (server performance)50 x 5-10 K = 0.25–0.5 Mbyte… on 2 bars of GSM!
Flickr experience
on desktop:
– select required files
– categorise and tag
on send
– starts to work
– failure
– some files uploaded, but untagged
– no ability to restart
Flickr– why?
code (on send)– upload all images
– tag all images
could be– build to-do list
– for each item in to-do list• upload and tag
– on restart: pick up last to-do-list …
on fail exit but save to-do list
on fail exit
software architecture
asynchronous interactions
distributed system not thin client
– synchronisation technology – inc. partial sync.
think local connectivity –
– e.g. Qraqrbox (cf. www paper)
think failure / restart
– e.g. to-do list based coding
protocols
IP slow start
– resilient to nuclear war… but not Tiree or Wales coast
DNS failure caching
why glitches???
router overload ?
policy
the netprivilege of the rich
or service for all
always connected?
mobile signalabsent or weak
broadband ...not so broad
masts point to seanot land ...yachts = money
https://explore.ee.co.uk/coverage-checker
infrastructure or privilege?
what is the greatestBritish invention?
infrastructure or privilege?
19th century – Penny Post
the amazing invention
revolutionised communication
Today – Internet
2013 – 50% of Welsh schools said
poor connectivity hampers education
2017 – 7 out of 20 worst connected areas in UK …… in Wales
http://www.victorianweb.org/history/pennypos.html
nudge, nudge
mobile mast charging
– similar to European roaming
– change cost-benefit for companies
– allow more community masts
ISPs & local communities
– Tiree local traffic goes to London and back!
glitches?
no official word for it!
=> not in agreementsnot in contracts
not noticed …… unless you have to live with it
in summary
user experience– on-going issue
– impact for individuals, business and education
policy– root cause – privilege or public service?
– vocabulary matters
architecture– good design ameliorates poor infrastructure
