Due to the large increasing use of Location Based Services (LBS), which require personal data of the user to provide the continuous service, protecting the privacy of these data has become a challenge. An approach to preserving a privacy is through anonymity, by hiding the identity and user location data of the mobile device from the service provider(third party) or from any unauthorized party who has access at the user’s request .Considering the challenge mentioned, in this paper gives a classification according to the Architecture, approaches and techniques used in previous works, and presents a survey of solutions to provide anonymity in LBS including the open issues or possible improvements to current solutions. All of this, in order to provide guidelines for choosing the best solution approach to a specific scenery in which anonymity is required.
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Dynamic grid system, cloaking areas, location based services, Encryption ,privacy.