simulation: start with downlink control

1 files changed, 90 insertions, 22 deletions

diff --git a/simulation.scm b/simulation.scm
index dd78fa1..d3f2c96 100644
--- a/simulation.scm
+++ b/simulation.scm
@@ -7,8 +7,21 @@
   #:use-module (ice-9 match)
   #:use-module (fibers)
   #:use-module (fibers channels)
+  #:use-module (fibers operations)
   #:use-module (fibers timers))
 
+(define (put-message/timeout chan msg to)
+  (perform-operation (choice-operation
+                       (sleep-operation to)
+                       (put-operation chan msg))))
+
+(define (get-message/timeout chan to default)
+  (perform-operation (choice-operation
+                       (wrap-operation (sleep-operation to)
+                         (lambda _ default))
+                       (get-operation chan))))
+
+
 (define RX1 1) ; s (has to be between 1-15s)
 (define RX2 (1+ RX1)) ; s
 (define RECEIVE_DELAY1 1) ; s
@@ -87,6 +100,7 @@
   (random 2.))
 
 (define (make-class-a id initial-channel upstream-chn downstream-chn)
+  (define window (make-channel))
   ;; Make all atomic
   (define channel initial-channel)
 
@@ -101,16 +115,23 @@
 
   ;; Handle the receive windows
   (define listening? (make-atomic-box #f))
-  (define (start-listening!)
+  (define (start-waiting-for! chn frame-counter)
     (ll "Device ~a started listening" id)
-    (atomic-box-set! listening? #t))
-  (define (stop-listening!)
+    (atomic-box-set! listening? (list chn frame-counter)))
+  (define (stop-waiting!)
     (ll "Device ~a stopped listening" id)
     (atomic-box-set! listening? #f))
-  (define (im-listening?)
-    (atomic-box-ref listening?))
+  (define (waiting-for? chn frame)
+    (let ((listen (atomic-box-ref listening?)))
+      (and listen
+           (= chn (car listen))
+           (= (frame-FCnt frame) (cadr listen)))))
 
-  (define (confirm frame-FCnt)
+  (define (process-downlink! frame)
+    ;; TODO
+    (ll "Device ~a got downlink frame ~a" id frame))
+
+  #;(define (confirm frame-FCnt)
     (when  (eq? frame-FCnt (atomic-box-compare-and-swap! to-confirm frame-FCnt #f))
       (spawn-fiber
         (lambda () "confirm confirmation frame"))))
@@ -134,12 +155,28 @@
         (ll "Device ~a waiting for data" id)
         (sleep (rand-time))) ;; wait for more data
       (send-uplink-frame current-frame id #t)
-      (set! current-frame (1+ current-frame)) ;; TODO: fix
-      (sleep RECEIVE_DELAY1)
-      (start-listening!)
-      (sleep RX1)
-      (stop-listening!)
-      (when (atomic-box-ref to-confirm)
+      (set! current-frame (1+ current-frame)) ;; TODO: improve
+      (sleep RECEIVE_DELAY1) ;; TODO: make sure this is ok
+
+      (start-waiting-for! channel (1- current-frame))
+      (let ((maybe-downstream-event (get-message/timeout window RX1 #f)))
+        (match maybe-downstream-event
+          (($ <radio-event> 'downlink-start chn frame)
+           (let ((event (get-message window)))
+             (stop-waiting!)
+             (match event
+               (($ <radio-event> 'downlink-end chn frame)
+                (process-downlink! frame))
+               (_ #f))))
+          (_ (stop-waiting!)))
+
+        #;(when (in-time?)
+          (wait-until-rx2)
+          (start-waiting-for! answer-to-x)
+          (open-RX2)
+          (stop-waiting! answer-to-x)))
+
+      #;(when (atomic-box-ref to-confirm)
         (sleep (- RECEIVE_DELAY2 RECEIVE_DELAY1 RX1))
         (start-listening!)
         (sleep RX2)
@@ -147,10 +184,17 @@
 
   (define (downstream)
     (forever
-      (let ((msg (get-message downstream-chn)))
-        (when (im-listening?)
-          (match (frame-body msg)
-            ('ack (confirm (frame-FCnt msg))))))))
+      (let ((ev (get-message downstream-chn)))
+        ;; TODO:
+        ;; If the same message is sent by several gateways how to identify
+        ;; which start corresponds to each end??
+        (match ev
+          (($ <radio-event> type chn frame)
+           (when (waiting-for? chn frame)
+             ;; do not add timeout if it's waiting for an end???
+             (spawn-fiber (lambda ()
+                            (put-message window ev)))
+             ))))))
 
   (lambda ()
     (spawn-fiber upstream)
@@ -160,7 +204,17 @@
   (define time-on-air 0.01) ;s (TODO)
   (define pending-interferences '())
 
-  (define (forward-frame x)
+  (define (send-to-device frame)
+    (ll "Trying to downlink")
+    (spawn-fiber
+      (lambda ()
+        ;; TODO: choose channel properly
+        (ll "Gateway ~a sending downlink ~a" id frame)
+        (put-message radio (make-radio-event 'downlink-start 0 frame))
+        (sleep time-on-air)
+        (put-message radio (make-radio-event 'downlink-end  0 frame)))))
+
+  (define (send-to-network-server x)
     (ll "Gateway ~a forwarding ~a" id x)
     (put-message network (make-network-event id x)))
 
@@ -169,6 +223,8 @@
     (forever
       (let* ((ev (get-message in)))
         (match ev
+          (($ <network-event> id frame)
+           (send-to-device frame))
           (($ <radio-event> 'uplink-start channel-n frame) #f)
           (($ <radio-event> 'interference channel-n frame)
            (set! pending-interferences (cons ev pending-interferences)))
@@ -179,7 +235,7 @@
                                     pending-interferences)))
              (set! pending-interferences not-mine)
              (when (null? mine) ;; TODO
-               (forward-frame frame)))))))))
+               (send-to-network-server frame)))))))))
 
 
 (define (make-radio in end-devices gateways)
@@ -238,8 +294,8 @@
                (frame-FCnt frame)
                channel-n)
            (use-lorawan-channel! channel-n ev)
-           (let ((chan (hash-table-ref end-devices
-                                       (frame-DeviceAddr frame)))
+           (let ((chan (device-channel (hash-table-ref end-devices
+                                                       (frame-DeviceAddr frame))))
                  (ints (interferences ev channel-n)))
              (put-message chan ev)
              (for-each
@@ -261,7 +317,7 @@
                    (put-message (device-channel gateway) ev))))))
 
           (($ <radio-event> 'downlink-end channel-n frame)
-           (ll "Device ~a ended uplink-frame #~a on channel ~a"
+           (ll "Device ~a ended downlink-frame #~a on channel ~a"
                (frame-DeviceAddr frame)
                (frame-FCnt frame)
                channel-n)
@@ -278,7 +334,19 @@
     (forever
       (match (get-message upstream)
         (($ <network-event> gateway-id frame)
-         (ll "Network event happend!"))))))
+         (ll "Network event happend!")
+         ;; TODO answer properly
+         (spawn-fiber
+           (lambda ()
+             (sleep RECEIVE_DELAY1)
+             (put-message
+               (device-channel (hash-table-ref gateways gateway-id))
+               (make-network-event
+                 gateway-id
+                 (make-frame (frame-FCnt frame)
+                             (frame-DeviceAddr frame)
+                             #f
+                             'hello))))))))))