Shopping on line can be easy, simple and save you lots of money. It can also take a lot of your time, frustrate you, and result in unwanted purchases. Now the same can be said for regular high street shopping, but with the vast opportunity presented by the Internet it will pay you to spend a few minutes reading this and understanding how to better optimize your Assisted Gps shopping experience:
1. Compare - without doubt the biggest advantage that the Assisted Gps offers shoppers today is the ability to compare thousands of Assisted Gps at a time. This is a great thing, but not necessarily all the time! Too much can be daunting at times so take advantage of the great comparison sites and where possible let them do the hard work for you.
2. Research - if it has been said it will be on the internet. Ignorance is no longer a justifiable reason for buying the wrong thing. Take the time to research in detail everything that you could possible want to know about
3. Testimonials - don't know anybody that has bought a Assisted Gps? Wrong! If the Assisted Gps is good the internet will let you know. Use the Internet as a friend and get testimonials before you buy.
4. Questions - Got a question about Assisted Gps then search the Forums, FAQ's, Blogs etc. Don't be afraid to ask .....
5. Reputation - Never heard of the company selling Assisted Gps? Don't worry, no reason why you should know every company in the world, but you know someone that does! Use the internet to find out what people are saying about Assisted Gps and build up a picture of their reputation for sales, returns, customer service, delivery etc.
6. Returns - still worried that even after all of the above your Assisted Gps wont be what you want? Check out the returns policy. There is so much competition now that someone, somewhere is bound to offer the terms that you are comfortable with.
7. Feedback - happy with your Assisted Gps then let people know, after all you are depending on others people input in your buying decision, so why not give a little back.
8. Security - check for the yellow padlock on the Assisted Gps site before you buy, and the s after http:/ /i.e. https:// = a secure site
9. Contact - got a question about Assisted Gps, or want to leave a comment then check out the sites contact page. Reputable companies have them and respond.
10. Payment - ready to pay for your Assisted Gps, then use your credit card or PayPal! Be aware of companies that don't accept them, there may be genuine reasons but given the huge amount of choice you have when buying online there is no reason at all not to buy via credit card or PayPal.
Global positioning system is a
satellite based positioning system.
Assisted GPS, or
A-GPS was introduced to enhance performance.The development of
A-GPS was accelerated by the U.S. Federal Communications Commission's
E911 mandate requiring the position of a
cell phone to be available to emergency call dispatchers.
Conventional GPS then had difficulty providing reliable positions in poor signal conditions. For example when surrounded by tall buildings (as a result of
multipath), or when the satellite signals are weakened by being indoors or under trees. Some newer receivers fare better.
In addition, when first turned on in these conditions, some non-
A-GPS units may not be able to download the almanac and ephemeris information from the GPS satellites, rendering them unable to function until a clear signal can be received continuously for up to one minute.
An
A-GPS receiver can address these problems in several ways, using an
Assistance Server:
- The Assistance Server can locate the phone roughly by what cell site it is connected to on the cellular network.
- The Assistance Server has a good satellite signal, and lots of computation power, so it can compare fragmentary signals relayed to it by cell phones, with the satellite signal it receives directly, and then inform the cell phone or emergency services of the cell phone's position.
- It can supply ephemeris for the GPS satellites to the cell phone, enabling the cell phone to lock to the satellites when it otherwise could not, and autonomously calculate its position.
- It can have better knowledge of ionospheric conditions and other errors affecting the GPS signal than the cell phone alone, enabling more precise calculation of position. (See also Wide Area Augmentation System)
Some
A-GPS solutions require an active connection to a cell phone (or other data) network to function, in others it simply makes positioning faster and more accurate, but is not required.
As an additional benefit, it can reduce both the amount of CPU and programming required for a
GPS Phone by offloading most of the work onto the assistance server. (This is not a large amount for a basic GPS - many early GPSs ran on 386/16 or similar hardware).
High Sensitivity GPS is an allied technology, that addresses some of the same issues in a way that does not require additional infrastructure.It notably cannot provide instant fixes when the phone has been off for some time, that some forms of A-GPS can.
See also
External links
- AssistNow Online and Offline A-GPS Services - u-blox
- Instant positioning anytime and under any signal conditions - AssistNow Online article - u-blox
- Article from GPS World - Assisted GPS: A Low-Infrastructure Approach
- Everything you want to know about E911 and E112 - many E911 & E112 related links
- Global Locate AGPS Overview
- Septier Communication Assisted GPS Implementation
Global positioning system is a
satellite based positioning system.
Assisted GPS, or
A-GPS was introduced to enhance performance.The development of
A-GPS was accelerated by the U.S. Federal Communications Commission's
E911 mandate requiring the position of a
cell phone to be available to emergency call dispatchers.
Conventional GPS then had difficulty providing reliable positions in poor signal conditions. For example when surrounded by tall buildings (as a result of
multipath), or when the satellite signals are weakened by being indoors or under trees. Some newer receivers fare better.
In addition, when first turned on in these conditions, some non-
A-GPS units may not be able to download the almanac and
ephemeris information from the GPS satellites, rendering them unable to function until a clear signal can be received continuously for up to one minute.
An
A-GPS receiver can address these problems in several ways, using an
Assistance Server:
- The Assistance Server can locate the phone roughly by what cell site it is connected to on the cellular network.
- The Assistance Server has a good satellite signal, and lots of computation power, so it can compare fragmentary signals relayed to it by cell phones, with the satellite signal it receives directly, and then inform the cell phone or emergency services of the cell phone's position.
- It can supply ephemeris for the GPS satellites to the cell phone, enabling the cell phone to lock to the satellites when it otherwise could not, and autonomously calculate its position.
- It can have better knowledge of ionospheric conditions and other errors affecting the GPS signal than the cell phone alone, enabling more precise calculation of position. (See also Wide Area Augmentation System)
Some
A-GPS solutions require an active connection to a cell phone (or other data) network to function, in others it simply makes positioning faster and more accurate, but is not required.
As an additional benefit, it can reduce both the amount of
CPU and programming required for a GPS Phone by offloading most of the work onto the assistance server. (This is not a large amount for a basic GPS - many early GPSs ran on 386/16 or similar hardware).
High Sensitivity GPS is an allied technology, that addresses some of the same issues in a way that does not require additional infrastructure.It notably cannot provide instant fixes when the phone has been off for some time, that some forms of A-GPS can.
See also
External links
- AssistNow Online and Offline A-GPS Services - u-blox
- Instant positioning anytime and under any signal conditions - AssistNow Online article - u-blox
- Article from GPS World - Assisted GPS: A Low-Infrastructure Approach
- Everything you want to know about E911 and E112 - many E911 & E112 related links
- Global Locate AGPS Overview
- Septier Communication Assisted GPS Implementation
