Mobile system

Câu 1 Nội dung câu hỏi GSM là viết tắt của A. Global System for Mobile Technology B. Global System for Mobile Communications C. Global Shared Memory D. General System for Mobile Communications Tần số làm việc của hệ thống GSM là: a) 800 và 1800 Mhz b) 800, 900, 1800 và 1900 Mhz c) 900, 1800, 1900 Mhz d) 900, 1800

24p phanconglai 13-10-2012 659 178   Download

Vào cuối những năm 1940, lần đầu tiên dịch vụ điện thoại qua sóng radio được giới thiệu, và đã được thiết kế cho người dùng trong những chiếc xe ôtô tới các mạng điện thoại viễn thông công cộng. Sau đó, vào thập niên 60, một hệ thống bởi Bell Systems được ra mắt, gọi là IMTS, hay " Improved Mobile Telephone Service", . Then, in the 60’s, a system launched by Bell Systems, called IMTS, or, “Improved Mobile Telephone Service", mang lại khá nhiều cải tiến như quay số trực tiếp và băng thông rộng hơn....

32p ctxn52 27-09-2013 119 17   Download

A bit (binary digit) is the smallest unit of information • N = 2n where N is the number of representations and n is the number of bits (ex. ASCII, Unicode, PCM code etc.) • Data communications transfer information using codes that are transmitted as signals (either analog or digital) • In general, analog lines provide a slow service that contains high error rates.

59p trungkiendt9 24-04-2011 99 18   Download

The Distribution system interconnects multiple BSSs. 802.11 standard logically separates the wireless medium from the distribution system – it does not preclude, nor demand, that the multiple media be same or different. An Access Point (AP) is a STA that provides access to the DS by providing DS services in addition to acting as a STA.

100p nammo0168 15-05-2011 120 33   Download

The AMS(R)S provides voice and data connectivity to users such as air traffic controllers, pilots and aircraft operators The AMSS comprises satellites, aeronautical earth stations (AESs), ground earth stations (GESs) and associated ground facilities such as a network coordination center. 7 Existing satellite systems in operation for aeronautical communications Inmatsat, MTSAT Iridium

30p hanampro91 10-05-2013 76 8   Download

High Frequency Data Link, or HFDL, is part of ARINC’s GLOBALink end-to-end communication system The HFDL system is a segment of the Aircraft Communications Addressing and Reporting System (ACARS) used to exchange Airline Operational Control (AOC) and Air Traffic Control (ATS) messagesbetween aircraft end systems and corresponding ground-based stations. GLOBALink/HF provides HF-based, air-to-ground digital communications with aircraft using ARINC 635 protocol. The HFDL system uses the principles of geographic diversity and frequency diversity to optimize HF propagation...

35p hanampro91 10-05-2013 66 4   Download

A PLMN can be regarded as an independent telecommunications entity. ▪ A PLMN is defined as: ▫ One or more switches with: ▫ Switches act as the interface to ▪ a common numbering plan ▪ a common routing plan external networks ▪ The PLMN can be separated into ▫ Core Network ▫ Access Network

359p donghoadequan 27-07-2013 73 7   Download

Chương 3 giới thiệu một số hệ thống điện thoại di động như: Các hệ thống điện thoại di động thế hệ thứ nhất (Hệ thống điện thoại di động kỹ thuật tương tự, Advanced Mobile Phone System), các hệ thống điện thoại di động thế hệ thứ hai (Global System for Mobile Communication). Mời các bạn cùng tham khảo để nắm bắt các nội dung chi tiết.

52p namthangtinhlang_04 15-11-2015 157 36   Download

Chương 3 giới thiệu về các hệ thống điện thoại di động. Trong chương này, người học sẽ tập trung tìm hiểu hai hệ thống điện thoại di động, đó là các hệ thống điện thoại di động thế hệ thứ nhất và các hệ thống điện thoại di động thế hệ thứ hai. Mời các bạn cùng tham khảo để biết thêm nội dung chi tiết.

53p kiepnaybinhyen_04 15-12-2015 114 11   Download

Bài 10: Ví dụ về hệ thống nhúng mobile robot. Những nội dung chính trong chương này gồm có: Mobile robot, sơ đồ khối mobile robot (e-punk), tổng quan về e-punk, kết cấu cơ khí, mạch điện tử, thiết kế layout (PCB 4 lớp), DSP và các biến thể,... Mời các bạn cùng tham khảo.

23p lovebychance03 13-07-2021 47 9   Download

In this thesis, focus on the wireless links between devices equipped by deployed operating personnel and intermediary access point infrastructure. We use multi-radio (MR) platforms, wireless devices with multiple and diverse transceiver technologies, to produce robust and reliable links through adaptive control of available transceivers. Primarily, we study the application of intelligent control techniques, namely reinforcement learning (RL), for adaptive control over diverse transceivers to achieve the desired robustness and reliability under dynamic environmental conditions.

185p runthenight04 02-02-2023 8 2   Download

This project is focused on studying the biological effects of low-power RF radiation on the expression and function of mechanosensitive ion channel protein (Piezo-1). To evaluate the effects of long-term exposures, cells were exposed at the frequency of 1800 MHz and power of 17 dBm for a period of 2 and 4 hrs using the transverse electromagnetic (TEM) cell exposure system. To study the effects of short-term RF radiation (10 min), exposures emitted from the mobile phone headset at the frequency of 845 MHz and powers of -15 dBm and -5 dBm were applied to cell cultures.

141p runthenight04 02-02-2023 11 3   Download

Modelling the diffusion of mobile commerce in a country is a difficult task due to the non-linear, complex and uncertain nature of its operating environment. Conventional analytical techniques are of limited use in this context, and a System Dynamics approach is more appropriate to model such a complex system.

295p runthenight04 02-02-2023 10 3   Download

Overall objective: Based on the proposed theoretical basis, the thesis analyzes the current situation and from that proposes solutions for investment capital for marine economic development in the South Central region in the coming time.

27p themeg 02-06-2021 61 4   Download

Researching methods of controlling pan-tilt tracking moving target using image information from 2 cameras with many uncertain parameters. Developing algorithms for controlling integrated system include mobile robot, pan-tilt and two cameras tracking moving targets.

27p gaocaolon6 30-07-2020 80 4   Download

This paper explores the effect of cloud based mobile learning on education competencies of engineering students.

8p lucastanguyen 01-06-2020 27 2   Download

This paper focuses on the study of customer preferences and its related factors regarding Android Mobile Applications which is both exploratory and descriptive. Anova, a statistical tool was used to test the hypothesis.

11p guineverehuynh 22-06-2020 10 1   Download

In this study, behaviors of gas inside the extraction chromatography column were investigated through experiments and Computation Fluid Dynamics (CFD) simulation. N2 gas once accumulated as bubbles in the packed bed was hardly discharged by the flow of mobile phase.

8p christabelhuynh 31-05-2020 12 2   Download

The thesis aims to propose some control techniques for mobile target Robot-camera. After that, I studied some of the torque control techniques of joints for the Robot-camera system sticking to the mobile target and the Robot-camera system, paying attention to the motivating motor sticking to the mobile target. Finally, the author also proposed some control algorithms for Robotic-camera arm system with irregular model, external noise and preventing system degradation, using nonlinear sliding controller (TSMC) in combination with Artificial neural networks to estimate uncertain numbers.

31p xacxuoc4321 09-07-2019 28 2   Download

Định nghĩa GSM: GSM là viết tắt của từ " The Global System for Mobile Cpommunication". Mạng thông tin di động toàn cầu. GSM là tiêu chuẩn chung cho các thuê bao di động di chuyển giữa các vị trí địa lý khác nhau mà vẫn giữ được liên lạc .

11p robocon721993 09-12-2013 82 10   Download