This document tries to depicts some common aspects about the management of CGI, A-GPS and WiFi location technologies in outdoor environments. It includes the rol of Mobile Operators (LBS Infrastructure), Client components in the handset and Network Providers like Google or Navizon.

2. Contents
Most Common Outdoor Location Technologies
Access through MNO’s LBS Infrastructure:
General Schema
LBS Architecture
LBS Functions & Services
Access through mobile client components:
General schema
External Network Providers
Global Network Server
Comments & Conclusions

3. Most Common Outdoor Location Technologies
Technologies CellId A-GPS WiFi
General -From 2G to 3.5G networks - GPS, GLONASS, Galileo - Private/Public Wifi networks
-4G (LTE): Currently adopted/ported by
many MNOs . Location under testing
Based on -Server Cell (CGIId) - CGI - Signal from, at least, 3 visible - MAC Adresss
-TA (Timing Advanced) satellites - RxLevel
- RxLev (Signal strenght) - Ephemerides /Navigation DB - Several networks
E-CGI
- Neighbors cells (NMR/BSIC) - ToA + Filters (triangulation)
(triangulation/trilateration)
- Other approaches: TOA, AOA, E-TDOA, E-
OTD
Accuracy -Depends on cell type (femtocells, -TTFF concept -Depends on signal power
picocells, micro, macro) -Depends on number of visible -Typically from 50 m to 200 m
-Depends on density of antennas satellites and device capabilities
- Usual figures: (antenna and chipset installed)
- From 60 m to 800 m in urban env. - Data provided from Assistance
- From 1 km to 25 kms in rural env. server (SUPL Positioning Server)
-Typically from 3 to 10 m
Indoor notes - DAS Systems and Picocells could be - Next generation (GPS III) will be - Indoor WiFi requires other
possible approaches more accurate covering urban mechanisms that are not
canyons but it won’t cover included in this doc.
indoor env.
These location technologies can be accessed through Operator’s LBS infrastructure as well through client
components installed in the mobile device

4. Access through MNO’s LBS infrastructure – General Schema
Le Interface: Many Operators offer a public API for
LBS ASPs/LBS providing CGI+TA technology (Control
Plane Arch.). Some Operators provide also A-GPS
LBS technology (SUPL Arch.) - i.e. OMA MLP
Le interface SDP (Service Delivery Platform):
Optional platform. Provides a public
access point to MNO’s infrastructure
systems/capacities
Service Delivery Platform (SDP) establishing the appropriate call flow for
Other MNO’s
each incoming request - i.e Huawei SDP
Location Enabling Server (LES) LES (Location Enabling Server): Most of
big Operators have installed this
middleware as the central piece of the
Location System (LS) LBS infrastructure - i.e Genasys
GMLC SLP Positioning Platform
SS7/MAP msgs ULP msgs LS (Location System): Mandatory piece. Provides the
location engine to get the user’s position based on its
MSISDN/IMSI. It uses SS7 signaling channels to access
Network MNO’s network (HLR/VLR for CGI techno.). Under SUPL
SET
arch. this server is called SLP (SPC+SLC) and interacts
directly with the handset (SET) through Lup interface - i.e
Geolens from Commscope.

5. Access through MNO’s LBS infrastructure – LBS Architecture
WEB Portal O&M Billing Systems (Pre/PostPaid)
SSO
Provisioning System
SMS-C
Customer Care
MMS-C
WAP GW Statistic & Datawarehouse
IVR
Presence Server
Network Info DB Terminal Info DB
GIS/GeoServer
MNO’s LBS infrastructure can include a wide variety of systems and components.
Each installation requires specific plug-ins with the existing external systems: O&M,
Media GWs, Provisioning, Billing,.. and others LBS systems.
These plug-ins must develop the interface (std or proprietary) as well the MNO’s required
logic .
LES and LS systems must be prepared to allow all these adaptations as flexibly as
possible.

6. Access through MNO’s LBS infrastructure – LBS Functions/Services
There are a set of specific functions that must be
supported by the MNO’s LBS infrastructure:
Location Enabling Server (LES)
Location System (LS) • Full set of API services including:
- Location: Immediate, Tracking, Geo-fencing,
Around,…
Public/Private API - Provisioning of users and groups
- Messaging (SMS,MMS,USSD,…)
Security/Access Ctrl Mgmt
-Spatial (mapping, routing, direct/reverse
User Subscription Mechanisms geocode, POI searching, …)
Privacy Mgmt • Authentication & Authorization of requests
• User’s subscription: Auto provisioning, Initiated
Cache Mgmt
by user or App, with/without user’s ack,…
Single/Hybrid Location Engine • Privacy: Anonymous ID, MSISDN masking,,
Admin./Config. Tools when, where and who can request the location.
• Location Cache: Last known location per user
and per loc. Technology, max loc. Age per app.
• Intelligent switching between available loc.
Most of these advanced features are usually technologies
carried out by the LES middleware being • Admin. WEB Tools: Provisioning, Statistic and
compliant with the specific rules and policies of
each MNO System Configuration tools.

7. Access through MNO’s LBS infrastructure – General Schema
LBS • Through API functions & SDKs that every O.S
LBS
provides is the possibility to access the necessary
LBS
network parameters (MCC-MNC-LAC-CI,
LBS SSID/MACAddress, RxLev, …) as well as the GPS
data (Lat/Lon coordinates, speed and direction).
Server System
Client Component
Location API
• The client component can offer a public API for
Security/Privacy Mgmt
SMS /GPRS installed apps in the handset as well as external
Cache/QoP Mgmt
requests from the server side. This public API
could provide:
CGI WiFi -Immediate location function
BTLE
-Tracking under several modes (periodic
A-GPS NFC time, when cell change event occurs, when
some distance has been reached, …)
-Geo fencing capabilities
• This location component could have other
This client component could be offered to additional capabilities for security and privacy
Mobile Operators in a cooperative way within
purposes, policies to decide between available
the LES/LS systems.
technologies and intelligent self-learning.

8. Access through MNO’s LBS infrastructure – External Network Providers
• If this component is outside of the MNO’s
environment, a system is required that converts
Server System
Client Component the network information into geographic
Location API coordinates.
Security/Privacy Mgmt
SMS /GPRS
Cache/QoP Mgmt • This kind of system/DB is provided currently by
several vendors like the following :
o Google
o Navizon
o RxNetworks
o Combain (location-api)
Network Provider o Broadcom
• These network providers offer a simple API to
convert network data - GSM/UMTS, WiFi
networks and/or IP location - into Lat/lon/radius
• The request to this conversion service values.
can be done both from the client • The prices of this connection depends on the
component or the server side. number of hits per month, the type of
technology required and/or the desired
geographical area.

9. Access through MNO’s LBS infrastructure – Global Network Server
• The schema shows a global server system that
Client
Components maintains the connection with multiple network
Server providers (NP) such as:
Systems
• Improve the success resolution rate of the
conversion process worldwide and for all
Global Network Data Server Mobile Operators.
Advanced API • Provide all the benefits and capabilities of
Cache Mgmt each external provider under a single,
Decission Policies homogeneous and advanced interface.
• Maintain all data (solved and errors) in an
internal cache avoiding unnecessary requests.
• Establish periodic tests over each external
Network Network provider giving a level of quality, reliability and
Provider Provider accuracy. These values will determine policy
Network decisions based on, for instance:
Provider
• The type of network technology (WiFi,
2G, 3G, ....)
• The geographical area (country, city ...)
• The associated Operator

10. Comments & Conclusions (I)
1) About CGI
• The LS (MNO’s system) uses the private BTS DB of the Operator in order to evaluate
the final user’s position.
• In this DB, each CGIId register contains their X/Y coordinates , a coverage area and
additional radio electric parameters (antenna height/down tilt,power, horizontal beam
opening,…).
• The antenna coverage area has been calculated through empiric algorithms (UIT Rec)
within a data model of terrain (MDT) and taking into account the interferences
between sites.
• This BTS DB is maintained by the MNO’s Network team being usually highly dynamic.
• The daily changes that the MNO does over their network does not usually reflect
coherently over its BTS DB so it loses quality and reliability in their LBS services
(directly or indirectly supported).
• On the other hand, the BTS DB that has been collected by the external network
providers (NP) has reached a high quality as they now have a lot more devices
(cars/handsets) and have improved their hybrid algorithms (GPS+WiFi+CGI
measurements ) establishing a more realistic coverage area from each antenna.
• However, the NP has no immediate knowledge in its DB of all the MNO’s network
changes (new antennas, updates in existing ones,…).

11. Comments & Conclusions (II)
1) About CGI (cont)
• As the Network Provider does, the operator could facilitate the same network
conversion service using their own BTS DB.
• The operator could take advantage of the work done by these Network Providers
through a full scan of each CGIId against the external conversion service.
• Using their private data (site coordinates, power, azimuth radiation, beam opening,
etc) along with circular coverage returned by the Network Provider , it is possible to
determine a more exact coverage area of each cell.
• Moreover the operator keeps records of all user events through billing information
(CDRs) or network events (attach, detach, On / Off, ...).
• Keeping all this mass of information of movements about all MNO’s subscribers could
be complicated from the point of view of the Network Provider so the Operator can
have the ability to lead solutions such as:
• Emergency (112/911)
• Public warning systems (alert the population located in an emergency area)
• Traffic Incident Management

12. Comments & Conclusions (III)
2) About WiFi
• Many operators have a Hotspot BD with exact information about public and private
access points.
• These DB could be much more accurate than those established by the Network
Providers through their mapping processes. The Operator can get the exact address
where each customer has installed their routers (including which floor).
• However there are few operators offering this technology under public access.
3) About GPS/A-GPS
• Due to many tests and certifications of each mobile terminal, the Operator has had a
long delay in including this technology under their LBS infrastructure.
• Based on that, the public use of this technology is further consolidated through
individual client applications (maps viewers, navigation, POI searching and augmented
reality, etc).

13. Comments & Conclusions (IV)
• Under the outdoor scenario, it seems that the established order and priorities by the
existing components is to first try to get the CGI techno., then WiFi and finally access
the GPS as the most precise technology.
• The CGI technology, by itself, is still a valid technology for many applications and
services.
• The access to the CGI parameters does not consume any significant resources or
battery in the mobile device (being an alternative technology) when access to GPS /
WiFi is not needed.
• For example, under geo fencing logic, you can keep a continuous track under CGI
technology while the user is far from the alarm area switching to a more precise
technology when he/she is closest.
• Maybe, the most suitable way for a Mobile Operator (or for a handset
manufacturer) is the formalization of a generic component that could be preinstalled
on their terminals.
• This client component would enable the use of all available location technologies for
any LBS application (both local and external to the device) and should be prepared to
support indoor positioning technologies (Indoor WiFi, BTLE,…) in the near future.
• Finally, in the indoor world, the Operator may be an additional player through DAS
solutions, IP location and femto cells.

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