Archive for July 2007
Kisah Seorang Teman
Barusan dapat e-mail dari teman SMU. Sesama perantau di negeri orang. Dia sekarang terdampar di US sana, mulai dari zaman mahasiswa sampai sekarang bekerja di sana. Katanya, sedang mencari sesuap nasi, sepetak tanah, dan segenggam berlian. Terakhir ketemu kalo gak salah 2 tahun lalu di Duri. Hahaha, yang kenal saya di SMU pasti tau siapa yang sedang saya bicarakan. Sori Tom (nama samaran), aku udah berusaha memberikan informasi sesedikit mungkin.
Berikut kutipan e-mail yang saya terima (demi privasi, nama pelaku dalam e-mail disamarkan):
Digital Broadcasting: Why Digital? (A qualitative review)
Broadcasting is a mass communication method. The basic idea of broadcasting is to make information sent from one source can be received by multiple receivers.
Digital broadcasting system is a telecommunication system of sending and receiving information by means of digital signals. This information can be sounds, moving pictures, or data.
Before digital broadcasting systems emerged, information is broadcasted using analog signal. Analog signal is signal that is continuous both in time and amplitude. Analog signal can be used to convey information by making variations of its properties. This variation is equivalent or analogous to information it conveys. For example, electrical analog signal is used to convey information by varying the voltage or frequency of the signal. By this property, small fluctuations in analog signal are meaningful. Any small different in the signal means different information.
In contrast to analog signal, digital signal is discrete in time. The values of the signal are noted at fixed intervals rather than continuously (for example, every millisecond). In addition to that, the value, instead of being measured to the exact value, is approximated to certain precision. This will allow the value to be represented by limited number of digits. In other words, digital signal’s values are quantized.
