I'm trying to get glucose measurements from glucose meter (Contour One Plus) with Bluetooth LE. I'm able to connect to device. I don't know how to start with Record Access Control Point. I can discover all of characteristics and services. I am asking for an explanation of the theoretical basis.
So, If I'm connected to the device - the first step is to send a request to RACP that I want to read the data? And what happened next? If Response Code Values send value="success" I should look on Glucose Measurement characteristic?
Related
I'm using the Device Access Sandbox environment and getting a RESOURCE_EXHAUSTED error response from the API with the message set to "Rate limited".
How do I know when I'm going to hit the rate limit?
Rate limits have been implemented in Device Access Sandbox to prevent over-utilization of devices and services. Rate limits are configured slightly differently for API methods, commands, and device instances, so there are a few different ways you could be hitting a rate limit.
Typical usage of Device Access with Nest devices shouldn't hit the rate limit. For example, if you wish to keep a history of temperature and humidity changes for a Nest Thermostat, there's really no need to check the temperature and humidity values more than 10 times in a minute (the devices.get limit)—they do not fluctuate enough in that time period to make such granularity useful.
To see all the rate limits applied to the Sandbox, see User and Rate Limits.
Looking through the documentation I can't find a way to get the current status of the nodes (online/offline) using the network map service.
Is this already implemented?
I can find this information using OS tools but I would like to know if there is a Corda way for this task.
Thanks in advance.
This feature is not implemented as of Corda V3. However, you can implement this functionality yourself. For example, see the Ping Pong sample here that allows you to ping other nodes.
In the future, it is expected that the network map will regularly poll each node on the network. Nodes that did not respond for a certain period of time (as defined by the network operator) would be evicted from the network map. However, this period of time is expected to be long (e.g. a month).
Please also note that:
In Corda, communication between nodes uses message acknowledgments. If a node is offline when you send it a message, no acknowledgment will be received, and the node will store the message to disk and retry delivery later. It will continue to retry until the counterparty acknowledges receipt of the message
Corda is designed with "always-on" nodes in mind. A node being offline will generally correspond to a disaster scenario, and the situation should not be long-lasting
I'm currently studying for my upcoming examination of Computer Networks and am covering the section "Quality of Service". Here, a table is shown displaying requirements by application in terms of bandwith, delay, jitter and loss.
To clarify with a simple example:
APP | BANDWIDTH DELAY JITTER LOSS
-------------+------------------------------------------
Email | low low low medium
File share | high low low medium
...
I understand all but one of the examples provided in the book: remote login.
Remote login | low medium medium low
It is unclear to me why jitter is a 'medium requirement' to be considered when implementing a remote login system. As far as my understanding goes: jitter is an irregularity in the time base of a signal, which (when applied to networking) can cause variable delays in delivering packets. I can understand the importance of this in applications revolving around telephony, video-conferencing, etc., but am having trouble to understand its importance in remote login systems.
Any thoughts/help is (always) greatly appreciated! Thanks in advance!
My best guess is that jitter also causes out-of-order packages. While not strictly necessary for remote login applications, it does help if the returned output is in-order. Perhaps therefore, it's not useful to spend a lot of resources ensuring low litter, but small pay-offs are worth it.
Okay so, I read some more on the matter and found the following:
(Keeping in mind that we know that if our application is sensitive to jitter, it will definitely be subject to delay.)
"Remote control and login are very delay sensitive. Typically a user expects responsiveness on the order of tens of milliseconds during a remote login session."
Internetworking and Computing Over Satellite Networks (Y. Zhang)
"Since remote login should be characterised by high reliability, no bits must be affected by errors. To accomplish this, checks are carried out at destination and, in the event of an error, confirmation of correct recept is not sent, an event that causes the transmitter to resend the packet that incorrectly reached the destination. ... In general, remote login, and in particular audio and video on demand, telephony and video conferencing are, however, sensitive to jitter."
Handbook of Communications Security (F. Garzia)
This confirms the straightforward assumptions which were also made by #CX gamer in his answer.
I get how to calculate ping - current time minus the time stamp of the packet - but how do I create a time stamp in the first place? What synchronized concept of time can I use? Note: I use .NET 2.0.
It could be as simple as when you issue your ping request (I will explain this in more detail in a moment), you make note of the current time, and then, when the server/client responds with a pong, you make note of the time again. Subtracting the pong time from the ping time gives you the amount of time for the communication to go between the two applications.
Wikipedia describes ping in the following way:
In multiplayer online video games, MMOs, MMORPGs, MMOFPSs and FPSs ping (not to be confused with frames per second) refers to the network latency between a player's computer (client), and either the game server or another client (i.e. peer). This could be reported quantitatively as an average time in milliseconds... Rather than using the traditional ICMP echo request and reply packets to determine ping times, game programmers often instead build their own latency detection into existing game packets
What I like to do, is when I make a client and a server, I always write in a simple 'ping/pong' command. In short, a ping request is made by one application, when the other application receives it, and sends back a pong confirmation command. This is good for debugging, but for actual development and depending on the game, I usually piggy back this with a heart beat to make sure everything is running as it should. Hope that helps!
We have an office network and hundreds of calls are being made daily on land lines and mobiles with different cellular networks.
My idea is that we have a system that will check intelligently that on which cellular network we are going to call. The advantage of identifying the network is that, (assuming every type of cellular network SIM is installed in our system) system will call that number from the same network on which we are calling.
By doing this we can decrease the charges, as call on the same network has less fares then calling on another network.
So I want to ask, is there a way through which we can identify the network of called number?
Using Telephony API you can get the network information of incoming call, but for outgoing call you can no do same.