provides wireless communications services in mexico

... staff 10 Summary • Wireless technology can positively impact an organization in many ways • Wireless technology faces various challenges • Once a business has decided to invest in wireless technology ... advantage of wireless technology Increased Productivity • Having universal access to corporate data – Leads to increased productivity by employees • Survey by Cisco in 2001 showed that – By using a ... additional hours each day Increased Access to the Customer’s Own Data • Key factor in reducing business costs – Shift the burden of accessing a customer’s data from the business to the customer –...

Ngày tải lên: 13/09/2012, 11:16

... propagation delay Hopping sequences in the uplink and the downlink are also related The hopping sequence in the uplink direction is derived from the one in the downlink direction in by adding 45 MHz © ... orbiting satellites offering continental and worldwide communications, data, tracking, and paging services The experience gained from these networks in the next few years will provide valuable input ... answering from alerting: Currently, the alerting function resides in the same device used for answering In IMT-2000, the alerting device may be a pager and the answering device may be a terminal...

Ngày tải lên: 18/04/2014, 11:02

... researchers Informed consent for all informants was obtained prior to the beginning of the interview The selection of informants in the qualitative component was purposeful and intentional, aiming to ... regarding contracts Preference of health unit personnel regarding contracts % Basic health unit personnel Total Physicians Nurses Others Maintain indefinitely 17 21 22 13 Maintain until finding ... positive relation obtained between investment and productivity diminishes the possibility of increasing the investment to improve workers' labour conditions Increasing economic incentives, medical...

Ngày tải lên: 18/06/2014, 17:20

... 2011 Printed in Croatia A free online edition of this book is available at www.intechopen.com Additional hard copies can be obtained from orders@intechweb.org Recent Advances in Wireless Communications ... Modified CRLB During the process of deriving the HCRB, an important step involves taking the inverse of the Fisher’s information matrix In some cases, the inverse of the Fisher‘s information matrix ... research Finally, Part C consists of seven chapters that are devoted to applications and realizations Chapter is an introduction to topics at an inner receiver in wireless communications, including...

Ngày tải lên: 19/06/2014, 19:20

... higher in multicarrier communications than in single carrier communications because of intersymbol interference The mismatch or instability of the local oscillator inevitably causes an offset in ... tracked time-varying symbol timing offset, which results in time-varying phase changes Intercarrier interference comes into being another attached problem Because an error in the sampling frequency ... frequencies In this block, orthogonality in subcarriers is introduced In IFFT, the frequency domain OFDM symbols are converted into time domain OFDM symbols Guard interval is introduced in each OFDM...

Ngày tải lên: 19/06/2014, 19:20

... state information required at the receiver, we will introduce four types of combining schemes, including selection combining, switch combining, EGC, and MRC, in the following 2.1.1 Selection combining ... diversity (Giannakis et al., 2006) In this section, we first present various receive diversity schemes, including selection combining, switch combining, equal-gain combining (EGC), and MRC The well-known ... next-generation wireless communications In general, an MIMO system has capability to offer three types of antenna gains: diversity gains, multiplexing gains and beamforming gains A wide variety...

Ngày tải lên: 19/06/2014, 19:20

... ordering V-BLAST algorithms Beamforming Beamforming is a promising signal processing technique used to control the directions for transmitting or receiving signals in spatial-angular domain (Godara, ... Recent Advances in Wireless Communications and Networks Will-be-set-by -IN- TECH Symbol mapping Segment S/P Grouping CDD STBC GO-CDM Symbol mapping Segment S/P Grouping IFFT CP CDD Spreading IFFT CP ... be mainly determined by the groups and classes whose matrices Gg,c = Gmin g,c min Tg,c Rmin Tg,c g H (42) have the smallest common rank, denoted by min ˜ Dmin = rank(Gmin ) = rank Tg,c Rmin Tg,c...

Ngày tải lên: 19/06/2014, 19:20

... detection process taking into account the group size in the GO-CDM component while assuming that an efficient ML implementation, such as the one introduced in (Fincke & Pohst, 1985), is in use To this ... length in a lattice, including a complexity analysis, Math Comput 44: 463–471 Foschini, G (1996) Layered space-time architecture for wireless communication in a fading environment when using multi-element ... multiplexing in fading channels, IEEE Trans Commun 50: 1266–1273 116 22 Recent Advances in Wireless Communications and Networks Will-be-set-by -IN- TECH Meyer, C (2000) Matrix analysis and applied linear...

Ngày tải lên: 19/06/2014, 19:20

... time and accounting for diversity and suppressing noise in spatial 150 12 Recent Advances in Wireless Communications and Networks Will-be-set-by -IN- TECH diversity brunches Depending on amount of ... combined to for Z ( N ) In the intermediate case both components are combined according to (67) with more and more emphasis put on in- phase component X ( N ) as coherency increases with increase ... already under study in LTE under the Coordinated 166 Recent Advances in Wireless Communications and Networks Multipoint (CoMP) concept (3GPP LTE, 2007) that although not included in the current releases,...

Ngày tải lên: 19/06/2014, 19:20

... wireless/ optical architecture, In Proceeding of IEEE WCNC’10, 2010 Foschini, G J & Gans, M J (1998) On limits of wireless communications in a fading environment when using multiple antenna, Wireless Personal ... using the precoding vectors defined in (25) and considering (26), the received signal in (24) reduces to, B eq yk ,l = ∑ pb , k , l hb , k ,l sk ,l + nk , l b =1 (27) 176 Recent Advances in Wireless ... minimizing the sum of inverse of SNRs, and a closedform expression can be obtained Note that minimizing the sum of inverse of SNRs is similar to the maximization of the harmonic mean of the SINRs...

Ngày tải lên: 19/06/2014, 19:20

... deteriorate QoS in WLAN, such as increasing blocking probability in WLAN So the joint call admission control needs to be optimized to achieve the minimum blocking probability per Erlang in the integrated ... is a monotonically increasing continuous function of δ , while blocking probability and dropping probability in UMTS cell are continuous decreasing functions over δ in the interval between zero ... Handoff Issues in 4G Wireless Systems An Overview, Proceedings of International Latin American and Caribbean for 210 Recent Advances in Wireless Communications and Networks Engineering and Technology...

Ngày tải lên: 19/06/2014, 19:20

... code line 27 in Fig 2) To make it compatible with IPv6, lines indicated in Table should be replaced int main(int argc, char *argv[]) { int sockfd, newfd; socklen_t sin_size; struct sockaddr _in local; ... Advances in Wireless Communications and Networks one data stream between source and destination endpoints Multistream SCTP includes multistreaming, and finally, multihomed SCTP incorporates multihoming ... sockaddr _in6 remota6; host = gethostbyname2(argv[1], AF_INET6); local6.sin6_family = AF_INET6; local6.sin6_flowinfo = 0; local6.sin6_port = htons(MY_PORT); local6.sin6_addr = in6 addr_any; if((bind(sockfd,...

Ngày tải lên: 19/06/2014, 19:20

... source link when source link is 11-uplink or 16-uplink in nrtPS or 16-link in BE The second item means the increase in a number of 286 20 Recent Advances in Wireless Communications and Networks Wireless ... uplink and downlink in terminals In rtPS class and nrtPS class, BS assigns data grants to downlink, and polls to terminals in accordance with the reserved capacity for uplink in each terminal, ... Tul.rtPS is a convex monotonically increasing function of Ful.rtPS the same as rtPS of downlink 3.4 16-uplink in nrtPS and 16-link in BE In 16-uplink of nrtPS and 16-link of BE, also the arrival packets...

Ngày tải lên: 19/06/2014, 19:20

... terminals in 11a, as mentioned in 5.2 In area-B, the packet collision and loss in 11b further increase because of the increase in traffic, and the large number of retransmissions in MAC brings ... capable of sensing the environments, processing the information locally, or sending it to one or more collection points through a wireless link Day to day applications of WSNs is increasing from domestic ... established infrastructure In a Wireless Sensor Network, the individual nodes are capable of sensing their environments, processing the information locally, or sending it to one or more collection points...

Ngày tải lên: 19/06/2014, 19:20

... Architecture for Integrating Wireless Sensor Networks into the Internet of Things, Proceedings of 3rd Symposium of Ubiquitous Computing and Ambient Intelligence 2008, Springer Berlin/Heidelberg, ... Routing Protocol for Enhanced Efficiency in Wireless Sensor Networks Proceedings of 1st International Workshop on Parallel and Distributed Computing Issues in Wireless Networks and Mobile Computing ... sensing means of a CR, • Decide: represents all that implies some intelligence including learning, planning decision taking, • Adapt: reconfigures the radio, designed with SDR principles, in order...

Ngày tải lên: 19/06/2014, 19:20

... we define several vocabularies to represent the actions in removing an element in text/html document, and in changing the coding of a web page For MIME type t, suppose the set of transcoding operations ... (2008) Mixed Traffic Packet Scheduling in UTRAN Long Term Evolution Downlink, Proceedings of IEEE 19th International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC) 2008, pp.1-5, ... framework for instantiating customized application proxies Hua et al (2006) integrated content adaptation algorithm and content caching strategy for serving dynamic web content in a mobile computing environment...

Ngày tải lên: 19/06/2014, 19:20

... PEAK − I IN I −I ⋅ Δt = PEAK IN ⋅ tON C C (21) And the capacitor charging time, VC(t), is: Charge : ΔV = I IN I ⋅ (T − tON ) ⇒ ΔV = IN ⋅ ⋅ Δt(GSM ) C C (22) 400 Recent Advances in Wireless Communications ... conversion, remains without answer the topic of switched or linear conversion The advantages and drawbacks of linear regulation versus switched regulation are exposed in the following lines 1) Linear regulation ... does not fit within the wireless device This inconvenient could be overcome, to a certain extent, by means of distribute the capacity in several capacitors in parallel or by using the technology...

Ngày tải lên: 19/06/2014, 19:20

... Wireless Sensing Unit Wireless Sensing Unit Wireless Sensing Unit Wireless Sensor Network Server Fig An overview of the prototype wireless structural sensing system At the beginning of each wireless ... sensing channel for storing the sensor data For each sensing channel, at any point in time, only one of the stacks is used to store the incoming data stream While incoming data is being stored into ... embedded wireless sensing unit software is that it can continue collecting data from interfaced sensors in real-time as the wireless sensing unit is transmitting data to the server In its current...

Ngày tải lên: 19/06/2014, 19:20

... as lighting LEDs This can even power wireless equipment that is evolving today at a rapid pace In continuous cyclical motions, it is easy to continuously obtain electrical energy by using flat ... in Wireless Communications and Networks the changeable width of the actuator was mm This made it possible to change the tuning frequency within a range of about 300 MHz The change in the tuning ... to our daily lives In recent years, improvements in integrated technology of electronic circuits and the increasing multi-functionality of mobile terminals have led to the inclusion of a multitude...

Ngày tải lên: 19/06/2014, 19:20

... 2011 Printed in India A free online edition of this book is available at www.intechopen.com Additional hard copies can be obtained from orders@intechweb.org Advanced Trends in Wireless Communications, ... Trends in Wireless Communications In the following, the most commonly used fading distributions will be presented with respect to their PDFs and MGFs 3.1 The Rayleigh fading model The Rayleigh fading ... transmission strategies in fading channels against their theoretical maximum performance The main idea behind these transmission schemes is balancing of the link budget in real time, through adaptive...

Ngày tải lên: 19/06/2014, 23:20