China
Africa
Explore chapters and articles related to this topic
Charging and Rating Requirements for New Communication Means
Published in Thierry Van De Velde, Value-Added Services for Next Generation Networks, 2007
The vulnerability comes from malicious applications that would, using the customer’s identification credentials (login and password), consume the communications credit without the customer knowing. In the era of dial-up Internet access, dialers would use the computer’s modem to dial toll numbers. This threat became more stringent in NGN, where a dialer could force the local user agent to make even more invisible outbound calls over IP interfaces. Is it the NGNSP’s duty to protect its end users from these security risks?
Health effects of WiFi radiation: a review based on systematic quality evaluation
Published in Critical Reviews in Environmental Science and Technology, 2022
Stefan Dongus, Hamed Jalilian, David Schürmann, Martin Röösli
WiFi, also called WLAN (Wireless Local Area Network), is commonly used to connect devices and for Internet access. Typical applications are in private homes, schools, workplaces, and WiFi hotspots in cities and public transport. WiFi is based on the IEEE 802.11 family of standards, which uses various transmission protocols mostly in the frequency range of 2.400 to 2.484 GHz and 5.150 to 5.825 GHz (IEEE, 2016). Data packets are transmitted between multiple devices and access points using various types of modulations such as the multiple-input, multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM). Consequently, WLAN devices transmit short pulses (bursts) and the burst lengths and burst repetition rates are highly dependent on the actual data traffic in the network. The duty factor is the ratio of the pulse duration to the total period, which is usually low for WiFi communication (Khalid et al., 2011). In the absence of data traffic, only the access point transmits a short beacon signal, every 100 ms, which corresponds to a pulse rate of 10 Hz. In this situation, the crest factor, defined as the ratio of peak values to the effective value, is highest (about a factor of 100) (Schmid et al., 2020).
Using innovative smart water management technologies to monitor water provision to refugees
Published in Water International, 2020
Ryan W. Schweitzer, Ben Harvey, Murray Burt
Each of the monitoring devices needed to be configured before it could be deployed. For the GSM devices this involved installation of local SIM cards, setting the device’s mobile internet access point name, and registering the GSM modem with the proprietary dashboard service. For the LoRaWAN-enabled devices this involved waking up the devices for first use and registering them with the LoRaWAN packet service (Things Network). All devices needed to be adjusted in the following way: changing the measurement frequency (from every 30 minutes to every 3 hours), changing the timing of measurements (selecting hours of operation, e.g. from 8 am to 8 pm), and calibrating to the size of the reservoir within which the device was mounted. The process of configuration was documented and qualitatively rated by the UNHCR team on a scale from 1 (easiest) to 10 (hardest).
Opportunistic forwarding for user-provided networks
Published in International Journal of Parallel, Emergent and Distributed Systems, 2018
Efthymios Koutsogiannis, Lefteris Mamatas, Vassilis Tsaoussidis
Example incentive mechanisms for UPNs are: (i) the Less Than Best Effort approaches [15–17] that offer guest users the resources that are not utilized by the SAP users; (ii) the Messages on oFfer (MooF) [14] mechanism which is a credit-based incentive mechanism enabling device to device data exchange; (iii) the SMART [58] that is a credit-based schema assuming a central authority for virtual banking and the nodes decide to participate based on each particular reward and the requested class of service; and (iv) the Practical incentive (Pi) [59] that combines both reputation- and credit-based approaches, giving a credit when the message arrives to the destination and a better reputation even if the message does not reach the target. For example, the mobile broadband Internet access may have a diverse cost and performance, which may not be true for a WiFi connection in the area. Furthermore, the latency may be significantly lower for local services. The Open Garden [8] and the Karma [7] startups implemented two interesting mobile UPN models. The former approach exploits the diversity of user requirements and capabilities through crowd sourcing and the latter allows mobile users to become mobile WiFi hotspots, in exchange of a compensation. A categorization of the different UPN incentive models, including the mobile UPN approaches, can be found at [60].