voice-mail

1. Definition

1.1. features

2. how to use

2.1. on what kind of devices

3. advantages

3.1. speed

3.2. conveinence

3.3. easy to be widespread

3.4. people at all ages can use it

3.5. global service

3.6. More clear message conveying

3.7. New Idea

4. disadvantages

4.1. Business Hassle

4.2. Personal Hassle

5. User Experience

5.1. Survey

5.2. Analyse

6. background information

7. Applications

7.1. Speech Filing System (SFS)

7.2. Wechat/Whatsapp

7.3. VMX

7.4. IVR Voice Recognition

8. history

8.1. invention

8.1.1. the reason for creating voicemail

8.2. development

9. how voice-mail works

9.1. Central processor (CPU)

9.2. Disk controller

9.3. System disks

9.4. Telephone interface system