delivering location sensitive advertisements using wi-fi networks
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Delivering Location Sensitive Advertisements Using Wi-Fi Networks. Lenin Ravindranath S Anna University BE Computer Science Year of Graduation: 2006 Mentors: Ranveer Chandra, Joseph Joy, Jitu Padhye, Alec Wolman Microsoft Research Duration: 10 weeks. Motivation. - PowerPoint PPT PresentationTRANSCRIPT
Delivering Location Sensitive Advertisements Using Wi-Fi Networks
Lenin Ravindranath SAnna University
BE Computer ScienceYear of Graduation: 2006
Mentors:Ranveer Chandra, Joseph Joy, Jitu Padhye, Alec Wolman
Microsoft Research
Duration: 10 weeks
Motivation
Explosive growth in Wi-Fi Networks in the last few years Delivery of Advertisements over the Internet has become
a huge market as well Ads are targeted – relevant to the user
Location Sensitive Advertisements will be a very important market in the near future Google has announced Free WiFi Access in San Francisco MSN has introduced “Locate Me” feature
Scenario
Users with WiFi-equipped devices in a market/mall- Devices could be PDAs, laptops or phones.
Users receive ads from nearby stores, restaurants on their devices- Filter Ads based on preference of the user
Example
Ad: CoffeeDay at 13rd Cross
Ad: Hi-Style: 30% off on any purchase
of 1000 rupees or more
What all is close to
me?
CoffeeDayHi-Style (30% off…)
Is there an apparel store?
Hi-Style (30% off…)
Existing Approaches Client establish connection with an Access Point Client may also send Info about its Location Download Ads “Pull” model of Ad Delivery
Download Ads
Establish Connection
Goal
Send Ad Text over WiFi Networks Make it visible to all clients in the vicinity
Advertisement
Ad Ad
Wi-Fi Protocol - Beacons
Access Point
Beacon Packets
Network NameSSID: NYCWireless
Network NameSSID: T-Mobile
Networks Found
Connected
Connected
Our Idea
Send Ad Text as part of Beacon packets that announce Wi-Fi networks
Modify certain fields in the Beacon to carry Ads A software at the Client extracts Ad Text from the
Beacons seen “Push” Model of Ad Delivery
Location Sensitive:Only the Clients in the vicinity of the AP receive their Ads
AdCenter APat CoffeeDay
WiFi Beacon
Within 250 m of CoffeeDay
CoffeeDay close to me..
Hmm!
I love Hot Choc! Go to CoffeeDay
Coffee Day Drink of the day is Hot Chocolate
Client running our software
Advantages Beacons are not encrypted Advertising a network using a beacon does not mean that you have to
let clients “connect” to the network
Clients receive beacons (hence ads) even when they are not connected to any network
Clients receive beacons from other networks even when they are connected to a particular network
Can update Ad text to include dynamic information
Number of tickets left Daily specials in a restaurant Stock quotes
Approaches to Send Ads
Field carrying Ad Size Mechanism Pros Cons
SSID
Network Name
32
bytes Break ad into fragments Send in successive Beacons Client reassembles Ad from multiple beacons
When Ad sent in
BSSID/ BIE
SSID is “AdCenter”
- User level client software- Works with non-windows clients
- Low Bandwidth- Spam
BSSID
Unique Identifier
6
bytes
- User level client software- Prevent Spam
Lowest Bandwidth
BIE
Vendor Specific Information
256
bytes
- Higher Ad Bandwidth- Prevent Spam
Kernel modifications at clients
3 approaches, each with its own pros and cons
Implementation Details – AP Access Points
Provide Interface to Specify Ads Fragment Long Ads Overload in Beacons sent
Modify Access Points Modify AP Driver
Software Access Points Wireless Card with modified Driver Send beacons constructed at User Level Effective for broadcasting Ads
Approaches
Implementation Details - Client
Software at Client Query Beacon fields Reassemble Ads Display to user User Preferences
No driver modification at the client required
Connected to Google Network
Still receive Ads from MSNAd
Client need not be connected to a network
Client can even be connected to a competitive network
Security
Sending Fake Ads JavaWorld near Coffee Day sends “Coffee Day is closed for a day”
Replay Attacks JavaWorld replays an Ad sent by Coffee Day at an earlier date
Unique ID includes a cryptographically secure signature, verifiable by
client-side software Only display ads that pass the test
The secure ID can be provided by MSN
Encrypt Ad and time of validity with MSN private key Decrypt at the client with MSN’s public key
Preferences
AdCenter AP at aShopping mall
WiFi Beacons
Coffee Day Drink of the day is Hot Chocolate
T-Mobile Internet at 20Rs
Preferences: See only ISPs
Preferences: See all Ads
Advertisements
Shop ISP Dynamic Info
Features - ISP Selection More details about the ISP without connecting to them
Dollars per hour Supported Rates Number of users connected etc
User connects to the ISP of his choice
Features - MapPoint
AP Sends Lat Long
Design - Access PointAd ConstructorAppend Ad with Custom Details
Type ISP Details Location Info
FragmenterDivide long Ads into Fragments
Append Unique ID Sequence Number More Frag Bit
Beacon ConstructorConstruct valid Beacon
With Ad Fragment in SSID/BSSID/BIE
Design - Client
Ad ParserParse AdExtract
Type ISP Details Location Info
Ad FilterFilter Ad based
User Preference Ad Type
Driver InterfaceQuery Beacon FieldsSSID, BSSID – XPAll fields – Vista/ Modified Clients
ReassemblyConstruct Ad from Fragments
Status Access Point
Software Access Point Send Ads in SSID/BSSID/BIE
- ISP Details- Location Details
Client Software Client GUI ISP Selection Map Point User Preferences Modified driver to query BIE
Collaborating with MSN
Paul Roy from MSN-IA, Tarek Najam from MSN AdCenter are already interested Demos schedules in Redmond in mid August
Revenue ModelsDeployment Scenarios
This is like.. How it works? Revenue Opportunities
APs at Stores Banner put up by a business in its own space
- MSN sells APs- Owners broadcast Ads
- Sale of Hardware- Sale of Software- Free/Paid WiFi Access
APs in Public Places
Billboards placed in prominent public places (malls or trains)
- Merchants bid to have their Ads delivered- Controlled by MSN Servers
- Charge of messages sent (depending on length, frequency etc)- Wi-Fi Access
APs at Home Banners placed on side of a residential building on a busy street
- Give away free APs with broadband connection- Customers allow MSN to send Ads
- Nearby Merchants bid to have their Ads delivered- Charge based on length, frequency etc
Backup Slides
Sending AdsApproaches
3 approaches, each with its own pros and conso SSID field of beacons carry Ad Message
SSID field identifies the network such as MSFTWLANo BSSID in beacons carry Ads
BSSID are 6 byte unique identifiers of an AP and can be set to any value
o InfoElement blob (BIE) in beacon packets carries Ad messages 802.11 allows to add vendor specific information
Metrics used to compare: Ease of deployment, Spam, Bandwidth for ads
Approach 1Use SSID field
SSID is network name with 32 byte limit Mechanism:
Break ad message into chunks < 32bytes each Successive beacons carry next chunk of ad message
Client software assembles the ad message
Beacon 1:
Beacon 2:
Starbucks: Coffee of the da
y is Mocha Java
Approach 1Use SSID field
Pros User level client software is enough Works with non-Windows Clients
Cons Low Bandwidth Spam
Approach 2Use BSSID field
Encode ad in BSSID Only 6 bytes per beacon packet All ads have same SSID, say “AdCenter” Client assembles ad message from multiple beacons
Pros User level client software Works with non-Windows clients Prevent Spam
Cons Lowest Bandwidth
Approach 3Add InfoElement Blob
Modify AP driver to add 256 byte ad message- Send larger ad messages in multiple blobs/beacons
Client driver modified to pass IE blob to user level- Driver changes not required for Vista Native WiFi cards
Pros Higher ad bandwidth Prevent Spam
Cons Kernel modifications at clients Limited support for non-Windows clients
Push vs Pull Model
Pull Model Push Model
Client explicitly associates with an AP and downloads Ads
Client need not associate with any AP to receive Ads
Client may also transmit information to the system about its location
Client does not transmit any information
Receive Ads only from the network connected
Receive Ads even when connected to competitive network
Higher Bandwidth for downloading Ads (54 Mbps)
Lower Bandwidth (200 Kbps)
Ads can be highly customized for individual users
Users set preferences to filter Ads
Raises concerns about privacy issues (client transmits identity and location)
Does not cause any privacy issues
Sending Long Ad Messages Fragment the Message and send in successive beacon Each message is of the form:
<UniqueID>
- This identifies the specific advertisement <SeqNo>
- Fragment number <More Flag>
- Are there more fragments left to come <Text>
- Text of this fragment User-level software on client reassembles all fragments, and
presents the advertisement to user
Preventing Spam All ads use the same SSID
E.g. “AdCenter”
This is the only extra network seen by users who do not run special client software
Ad text is sent as beacon option Decoded and displayed by MSN-specific client software
User creates a profile on their device to filter ad messages I do not want to see ads for shoes, but want to see ads for
electronics
Revenue Model 1APs at Stores
Banner put up by a business in its own space MSN sells special APs and associated software to business Owners broadcast appropriate Ads APs can provide Wi-Fi Access MSN can manage them this Wi-Fi Access
Revenue Opportunities Sale of Hardware Sale of the Associated Software Periodic Subscription to keep the cryptographic keys updates Managing the AP to provide free/paid Wi-Fi Access
Revenue Model 2APs in Public Places
Billboards placed in prominent public spaces (malls or train stations or buses)
MSN either rents are owns these “billboards” Merchants bid to have their ads delivered via these APs Controlled by MSN Servers Can also support free or paid WiFi Access
Revenue Opportunities MSN charge for messages sent
(depending on length, frequency etc) Provide Wi-Fi Access and charge
Revenue Model 2APs in Public Places
AdCenter AP on Commuter Bus
Ad
Starbucks Coffee of the day is Mocha Java 10 sec
Tully’s 10% off on opening account 20 sec
Borders NYT Bestsellers 20% off 1 min
B&N Amazon sucks! 5 min
Amazon B&N really sucks! 10 min
+
Shown Every …
$$$ decides Ad Frequency
Revenue Model 3APs at home
Banners placed on side of a residential building on a busy street
Form partnership with a broadband provider (Comcast) Give away Free APs to Customers Customers allow MSN to remotely program these APs to
send Ads
Revenue Nearby merchants bid to have their Ads
Fee Structure depends on length, frequency etc
FeaturesDistributing Coupons
Starbucks: Get 10% off a Hot Chocolate
Step 1: Coupon Distribution Step 2: Coupon Validation
Present coupon
Discounted Coffee
User does not have to connect to the Internet!