Mobile wireless communications are in constant evolution due to the continu- ously increasing requirements and expectations of both users and operators. Mass multimedia* services have been for a long time expected to generate a large amount of data traffic in future wireless networks [1]. Mass multimedia services are, by definition, purposed for many people. In general, it can be distinguished between the distribution of any popular content over a wide area and the distribu- tion of location-dependent information in highly populated areas. Representative examples include the delivery of live video streaming content (like sports compe- titions, concerts, or news) and file download (multimedia clips, digital newspa- pers, or software updates).
標(biāo)簽： Broadcasting Generation Mobile Next
上傳時(shí)間： 2020-05-31
上傳用戶：shancjb
We are currently witnessing an increase in telecommunications norms and standards given the recent advances in this domain. The increasing number of normalized standards paves the way for an increase in the range of offers and services available for each consumer. Moreover, the majority of available radio frequencies have already been allocated.
標(biāo)簽： Allocation Resource Radio
上傳時(shí)間： 2020-06-01
上傳用戶：shancjb
Mobile and wireless communication systems are a prominent communications technology of the twenty-first century with profound economic and social impacts in practically all parts of the world. The current state of wireless communication systems allows for a much wider scope of applications than what it used to be originally, that is, to be a mobile extension of the public switched telephone network.
標(biāo)簽： Allocation Resource MIMO and
上傳時(shí)間： 2020-06-01
上傳用戶：shancjb
The radio spectrum is one of the most precious resources which must be managed to ensure efficient access for the wireless communication services which use it. The allocation and management of spectrum are administered by the regulatory authorities. Traditionally, spectrum allocation is carried out exclusively of its use in large geographic areas and assigning frequency bands to specific users or service providers is proved to be inefficient. Recently, substantial knowledge about dynamic spectrum access scheme has been accumulated to enable efficient spectrum sharing.
標(biāo)簽： Management Spectrum Access and
上傳時(shí)間： 2020-06-01
上傳用戶：shancjb
The use of mobile devices now surpasses that of traditional computers: wireless users will hence soon be demanding the same rich multimedia services on their mobile devices that they have on their desktop personal computers. In addition, new services will be added, especially related with their mobile needs, such as location-based information services.
標(biāo)簽： Communications Technology Wireless Trends in
上傳時(shí)間： 2020-06-01
上傳用戶：shancjb
Resource allocation is an important issue in wireless communication networks. In recent decades, cognitive radio technology and cognitive radio-based networks have obtained more and more attention and have been well studied to improve spectrum utilization and to overcomethe problem of spectrum scarcity in future wireless com- munication systems. Many new challenges on resource allocation appear in cogni- tive radio-based networks. In this book, we focus on effective solutions to resource allocation in several important cognitive radio-based networks, including a cogni- tive radio-basedopportunisticspectrum access network, a cognitiveradio-basedcen- tralized network, a cognitive radio-based cellular network, a cognitive radio-based high-speed vehicle network, and a cognitive radio-based smart grid.
標(biāo)簽： Cognitive Networks Radio
上傳時(shí)間： 2020-06-07
上傳用戶：shancjb
Electric distribution networks are critical parts of power delivery systems. In recent years, many new technologies and distributed energy resources have been inte- grated into these networks. To provide electricity at the possible lowest cost and at required quality, long-term planning is essential for these networks. In distribution planning, optimal location and size of necessary upgrades are determined to satisfy the demand and the technical requirements of the loads and to tackle uncertainties associated with load and distributed energy resources.
標(biāo)簽： Distribution Electric Planning Network
上傳時(shí)間： 2020-06-07
上傳用戶：shancjb
With all the recent hype over radio frequency identification (RFID) and the requirements to implement it, you might think that RFID can turn water into wine, transform lead into gold, and cure the world’s diseases. You might also be worried that RFID will enable Big Brother to track your move- ments to within a foot of your location from a satellite five hundred miles up in space. The truth is, RFID can do none of these things. In this chapter, you find out the basics of what RFID is, what forces are dri- ving RFID as a replacement for the bar code in the marketplace, and what benefits RFID can offer
標(biāo)簽： ForDummies_RFID_For_Dummies
上傳時(shí)間： 2020-06-08
上傳用戶：shancjb
With more than two billion terminals in commercial operation world-wide, wire- less and mobile technologies have enabled a first wave of pervasive communication systems and applications. Still, this is only the beginning as wireless technologies such as RFID are currently contemplated with a deployment potential of tens of billions of tags and a virtually unlimited application potential. A recent ITU report depicts a scenario of “Internet of things” — a world in which billions of objects will report their location, identity, and history over wireless connections.
標(biāo)簽： Internet Things From The RFI of
上傳時(shí)間： 2020-06-08
上傳用戶：shancjb
一天學(xué)會(huì)用Allegro畫(huà)電源板Allegro 由于其相對(duì)完善、強(qiáng)大的功能，一向被認(rèn)為是較難學(xué)的畫(huà)板軟件之一，主要原因也是因?yàn)楣δ芴啵?如果按 500 多頁(yè)的出版教材來(lái)一一學(xué)是有點(diǎn)費(fèi)時(shí)的，其實(shí)，如果只是用來(lái)畫(huà)簡(jiǎn)單電源板的話，一兩天就可以學(xué)會(huì)了， 沒(méi)有很多命令要記，幾乎要用的命令都可以從下拉菜單中找到且大部分都已以直觀的圖標(biāo)按鈕形式分布在軟件主界 面上，即你可直接輸入命令也可以從菜單中操作，也可從工具欄中點(diǎn)“按鈕”，覺(jué)得哪種更方便就用哪種。該教程 只說(shuō)畫(huà)電源板用到的功能部分，使復(fù)雜工具變?yōu)楹?jiǎn)單、易學(xué)。如下圖是一塊用 Allegro 畫(huà)的單面電源板。 ————本教材主要 for 從用 Altium Designer 和 PADS 轉(zhuǎn)過(guò)來(lái)的工程師。完成板子的效率比 99SE 高得多。 一、 建原理圖 *目的是用于生成網(wǎng)表導(dǎo)入 allegro 中布局。（習(xí)慣不需原理圖和網(wǎng)表就能畫(huà)板的工程師請(qǐng)?zhí)?allegro 篇） 1.1 找個(gè)盤(pán)比如 D 盤(pán)建個(gè)項(xiàng)目文件夾，里面再建兩個(gè)文件夾，一個(gè)用于放電路原理圖，一個(gè)用于放 PCB 文件， 盡量不要中文名。PS：原理圖和 PCB 都放在同一個(gè)文件夾下也可以的，只是不好找不方便管理。 1.2 打開(kāi) Or CAD Capture CIS→File→New→Project，在 name 一欄填電路圖名稱；在 Create a New Project Using 一欄中選 PC Board Wizard;接下來(lái)一欄 Location 是選剛才建的文件夾路徑然后點(diǎn) OK 按鈕。
上傳時(shí)間： 2022-02-06
上傳用戶：
蟲(chóng)蟲(chóng)下載站版權(quán)所有 京ICP備2021023401號(hào)-1
