VRS Technology - A Detailed Look at the Future Architecture of VRS

Network Software

The technology behind the scene

Christian Pagels

Trimble® RTKNet(TM)

New Demands Modifications to satellite system

– GPS L2C, L5– Glonass improved L2, third

frequency

New satellite systems– Galileo– Compass– QZSS (Quasi Zenith Satellite System)

– IRNSS (Indian Regional Navigation Satellite System)

-> Larger Applications – More signals– More stations / more users– Increasing complexity of

models

New hardware– Multi core processor– 64 bit operating system– Faster memory access

New technologies– .Net– Microsoft Web Services – WCF

-> New opportunities

Trimble® VRS³Net(TM)

Trimble VRS³Net

Multi Layer Architecture / Module Layer

M o d u le La y e r

F u nc tio na lity

•Clearly defined communication channels

•One thread per Module Layer

•Separation between Functionality and UI

Multi Layer Architecture / Process Layer

P ro c e s s La y e r

M o d u le La y e r

F u nc tio na lity

M o d u le La y e r

F u nc tio na lity

•One application per process layer

•Shared memory communication

•Multi-Core-Processor support

Multi Layer Architecture / Computer Layer

P ro c e s s La y e r

M o d u le La y e r

F u nc tio na lity

M o d u le La y e r

F u nc tio na lity

P ro c e s s La y e r

M o d u le La y e r

F u nc tio na lity

M o d u le La y e r

F u nc tio na lity

Multi Layer Architecture / Computer Layer

C o m p u te r La y e r

P ro c e s s La y e r

M o d u le La y e r

F u nc tio na lity

M o d u le La y e r

F u nc tio na lity

P ro c e s s La y e r

M o d u le La y e r

F u nc tio na lity

M o d u le La y e r

F u nc tio na lity

. . .

•TCP / IP communication - .Net Remoting

•Memory protection between processes

Multi Layer Architecture / Multi Computer LayerM u lti C o m p u te r La y e r

C o m p u te r La y e r

P ro c e s s La y e r

M o d u le La y e r

F u nc tio na lity

M o d u le La y e r

F u nc tio na lity

P ro c e s s La y e r

M o d u le La y e r

F u nc tio na lity

M o d u le La y e r

F u nc tio na lity

. . .

C o m p u te r La y e r

P ro c e s s La y e r

M o d u le La y e r

F u nc tio na lity

M o d u le La y e r

F u nc tio na lity

P ro c e s s La y e r

M o d u le La y e r

F u nc tio na lity

M o d u le La y e r

F u nc tio na lity

. . .

. . .

•Load distribution

•Hardware redundancy

•Different operating systems

•Several security layers

Single Server

Receiver, Storage, Processing, Real time output, Monitoring

Multi Server

Receiver, Processing

Real Time Output

Storage, Monitoring

Multi core / Multi processor

• Separate modules for different tasks

• Each module runs on its own thread

• Modules grouped into processes

-> Multiple threads plus multiple processes

-> OS distributes threads on all available processors

Multi core / Multi processor

- 140 Stations

- Data Storage

- Ephemeris processing

-> Dual Quad Computer

-> 2.66 GHz

-> 4 Gb Ram

Ambiguity Search & FixAmbiguity Search & FixAmbiguity Search & Fix

Processor Parallelization

Geometric Filter

Geometric Filter

Geometric Filter

Raw DataAnalysis

Synchronizer

Geometric Filter

Ionospheric Filters

Code-Carrier Filters

Ambiguity Search & Fix

Residual ManagementNetwork Model

IntegrityVRS Generation

Raw DataAnalysis

Raw DataAnalysis

Raw DataAnalysis

Geometric Filters

Processor Parallelization

Federated Filter– A highly computational efficient approach to deal with

filters with large number of states– Bank of local filters runs in parallel

Parallel computing library –OPENMP– Powerful, compact, de-facto standard for shared

memory multiprocessing programming– Single source code, incremental development, multi

language support

More Information by Xiaoming Chen in INF 1926

Multi core / Multiprocessor

-140 Stations GNSS

- Data storage

- Network processor

- 150 VRS Rover

- Network Motion Engine on all Stations

Memory management

32 bit operating system

32 bit Application

4 Gb RAM

2 Gb Application 2 Gb OS

2 Gb Application 2 Gb OS

Memory management

Distribution on multiple processes / application on 32 bit OS

4 Gb RAM

2 Gb Application 2 Gb OS

2 Gb 2 Gb

2 Gb

Memory management

64 bit operating system

32 bit application

X Gb RAM

3 Gb App 3 Gb App 3 Gb App

Trimble VRS³Net

Trimble VRS³Net

Data base• Benefits

• No load within the real time system• Downtime does not influence the history displays• Information generation separated• SQL scheduled Backup• SQL build in redundancy

• Maintenance• Object lifetime• Limitation of table size• Reduction of history objects by merging• Defragmentation through index recreation• Cache files in case of inavailability

Trimble VRS³Net

Trimble VRS³Net

Report Generator

• Reports Generated on demand or scheduled• Based on a XML/SQL script language• Definition files not protected• HTML, XML, PDF, CSV, TXT supported

Report Generator – Definition files

Reports

Redundancy• Cold Standby

• Computer or Program needs to be started

• Warm Standby• Program is running, but needs re-initializing / re-connect

• Hot Standby• Program is running and initialized

Real time data flow

G N SS S tat io nN e two rkP ro c e s s o r

R TO N e t N tr ip C as te r VR S R o ve r

GSM Support through Ntrip Caster• One point of contact into the Network Server• Access limitation though Ntrip Caster

• GPRS – Ntrip• GSM – phone number

• User protection through Ntrip Caster• Dynamic allocation of RTO clients

G N SS S tat io nN e two rkP ro c e s s o r

R TO N e t N tr ip C as te r VR S R o ve r

G P R SN tr ip

VR S R o ve rAc c e s sSe rve r

G SM

Real time data flow

G N SS S tat io nN e two rkP ro c e s s o r

R TO N e t N tr ip C as te r VR S R o ve r

Mount point redundancy• Two control line connections per mount point

• Load distribution• Redundancy

G N SS S tat io nN e two rkP ro c e s s o r

R TO N e t N tr ip C as te r VR S R o ve r

G P R SN tr ip

R TO N e t

Real time data flow

Network redundancy• Multiple Networks feeding into RTO

• Calculate best model interpolation for network decision• Change network on the fly in case of network failure

(re-initialization)• Manually assign customer to a dedicated network• Use “Mobil rover option” also across networks

G N SS S tat io nN e two rkP ro c e s s o r

R TO N e t N tr ip C as te r VR S R o ve r

G P R SN tr ip

R TO N e t

G N SS S tat io nN e two rkP ro c e s s o r

R TO N e t N tr ip C as te r VR S R o ve r

N e two rkP ro c e s s o r

Real time data flow

Station handling• Add backup line to Router (TSM)• Add Storage Integrity into Receiver module• Smooth process to add new stations

G N SS Stat io nN e two rkP ro c e s s o r

R TO N e t N tr ip C as te r VR S R o ve r

N e two rkP ro c e s s o r

G N SS S tat io nN e two rkP ro c e s s o r

R TO N e t

N e two rkP ro c e s s o r

G N SS S tat io n

Real time data flow

Redundancy• Warm Standby for the connection to the Receiver• Cold / Warm / Hot Standby for the receiver modules• Hot Standby for the Network processor• Hot Standby for the RTO modules• Warm Standby for the Ntrip Caster

G N SS S tat io nN e two rkP ro c e s s o r

R TO N e t N tr ip C as te r VR S R o ve r

G P R SN tr ip

VR S R o ve rAc c e s sSe rve r

G SMN e two rkP ro c e s s o r

R TO N e t

Accounting

Three access levels:

• Authentication• Authorization• Subscription

Authentication

• GPRS: Ntrip Basic• GSM: Phone number• VRS³Net Web: Organization, Username, Password• VRS³Net Web Mobile: Organization, Username, Password

AuthorizationRole Management• Web Management

• User• Accounts• Subscriptions• Status

• Reference Data download• CORS • Virtual reference stations

• Ntrip Caster mount points• Single Station streams• Network supported streams

• Mail recipient• Register for new login• Subscription about to expire

Subscription

Resources• Dynamic content per client• Entry based on session• Time and/or amount

• Real Time Single Station RTK• Real Time Single Station DGPS• Real Time Network RTK• Real Time Network DGPS • Post Processing CORS• Post Processing VRS• Virtual Resources (customer defined)

Subscription

Contracts• Live time• Contract items

• Resource

• Cost type – Pre Paid or Billing

• Cost

• Pricing Style – Per-Unit or Per-Item

• Limit and Limit style

• Charging Style

• Time Base

• Priority

Subscription

Subscriptions• Client implementation of a contract

• Start date – End date

• Time benefits

• Detailed reports for billing

• Approval process for renewalS u b s c r ip tio n 2 0 0 8

S en d r em in d er to Ad m in is tr a to r r eg ar d in g "En d o f S u b s c r ip tio n "

S en d r em in d er to c u s to m er r eg ar d in g "E n d o f S u b s c r ip tio n "

S en d em ail to c u s to m er r eg ar d in g "Ap p r o v al o f R en ew al"

S en d em ail to c u s to m er r eg ar d in g "Ac tiv a tio n o f n ew S u b s c r ip tio n "

C r ea te r en ew al s u b s c r ip tio n b y VR S ³N et

Ap p r o v e S u b s c r ip tio n b y Ad m in is tr a to r

Ac tiv a te S u b s c r ip tio n b y "En d o f p r ev io u s s u b s c r ip tio n "

S u b s c r ip tio n 2 0 0 9

Subscription

• Distribution and Parallelization are the keys for the increased demands

• The new architecture is the right approach to utilize the new technology

• The new architecture allows VRS³Net to be maximum scalable, customizable and expandable.

•INF 1887: The Next Generation of Trimble VRS Network Solutions by Christopher Daub

•INF 1926: VRS Networks – The magic behind the scenes by Xiaoming Chen

Thank you very much for your attention

Questions???