diff --git a/change_log.md b/change_log.md
index 7f926baa..fde09816 100644
--- a/change_log.md
+++ b/change_log.md
@@ -14,11 +14,16 @@
 ## develop history ##
 ---
 
+- 2019/06/07
+    > Improvement
+    * use time.After instead of wheel.After
+    * add remark for tcp reading
+
 - 2018/10/16
     > Feature
     * add rpc/micro CallOneway/AsyncCall
     * version: v1.0.3
-    
+
 - 2018/08/19
     > Feature
     * use multiple service config in service configuration
@@ -32,7 +37,7 @@
 - 2018/08/13
     > Feature
     * Add Micro
-    
+
 - 2018/08/07
     > Improvement
     * RPC package format:  {2 Bytes Header len + Header + 2 Body len + Body} ---> {Header + Body}
diff --git a/client.go b/client.go
index f2f2b319..7ce27528 100644
--- a/client.go
+++ b/client.go
@@ -138,8 +138,7 @@ func (c *client) dialTCP() Session {
 		}
 
 		log.Infof("net.DialTimeout(addr:%s, timeout:%v) = error:%+v", c.addr, connectTimeout, err)
-		// time.Sleep(connInterval)
-		<-wheel.After(connInterval)
+		time.Sleep(connInterval)
 	}
 }
 
@@ -167,8 +166,7 @@ func (c *client) dialUDP() Session {
 		}
 		if err != nil {
 			log.Warnf("net.DialTimeout(addr:%s, timeout:%v) = error:%+v", c.addr, err)
-			// time.Sleep(connInterval)
-			<-wheel.After(connInterval)
+			time.Sleep(connInterval)
 			continue
 		}
 
@@ -177,8 +175,7 @@ func (c *client) dialUDP() Session {
 		if length, err = conn.Write(connectPingPackage[:]); err != nil {
 			conn.Close()
 			log.Warnf("conn.Write(%s) = {length:%d, err:%+v}", string(connectPingPackage), length, err)
-			// time.Sleep(connInterval)
-			<-wheel.After(connInterval)
+			time.Sleep(connInterval)
 			continue
 		}
 		conn.SetReadDeadline(time.Now().Add(1e9))
@@ -189,8 +186,7 @@ func (c *client) dialUDP() Session {
 		if err != nil {
 			log.Infof("conn{%#v}.Read() = {length:%d, err:%+v}", conn, length, err)
 			conn.Close()
-			// time.Sleep(connInterval)
-			<-wheel.After(connInterval)
+			time.Sleep(connInterval)
 			continue
 		}
 		//if err == nil {
@@ -228,8 +224,7 @@ func (c *client) dialWS() Session {
 		}
 
 		log.Infof("websocket.dialer.Dial(addr:%s) = error:%+v", c.addr, err)
-		// time.Sleep(connInterval)
-		<-wheel.After(connInterval)
+		time.Sleep(connInterval)
 	}
 }
 
@@ -307,8 +302,7 @@ func (c *client) dialWSS() Session {
 		}
 
 		log.Infof("websocket.dialer.Dial(addr:%s) = error:%+v", c.addr, err)
-		// time.Sleep(connInterval)
-		<-wheel.After(connInterval)
+		time.Sleep(connInterval)
 	}
 }
 
diff --git a/server.go b/server.go
index 8610e5b6..3b1c0725 100644
--- a/server.go
+++ b/server.go
@@ -233,8 +233,7 @@ func (s *server) runTcpEventLoop(newSession NewSessionCallback) {
 				return
 			}
 			if delay != 0 {
-				// time.Sleep(delay)
-				<-wheel.After(delay)
+				time.Sleep(delay)
 			}
 			client, err = s.accept(newSession)
 			if err != nil {
diff --git a/session.go b/session.go
index 34d638b1..01ac5b99 100644
--- a/session.go
+++ b/session.go
@@ -41,14 +41,6 @@ const (
 // session
 /////////////////////////////////////////
 
-var (
-	wheel = NewWheel(time.Millisecond*100, 1200) // wheel longest span is 2 minute
-)
-
-func GetTimeWheel() *Wheel {
-	return wheel
-}
-
 // getty base session
 type session struct {
 	name      string
@@ -337,7 +329,7 @@ func (s *session) WritePkg(pkg interface{}, timeout time.Duration) error {
 	case s.wQ <- pkg:
 		break // for possible gen a new pkg
 
-	case <-wheel.After(timeout):
+	case <-time.After(timeout):
 		log.Warnf("%s, [session.WritePkg] wQ{len:%d, cap:%d}", s.Stat(), len(s.wQ), cap(s.wQ))
 		return ErrSessionBlocked
 	}
@@ -510,7 +502,7 @@ LOOP:
 				log.Infof("[session.handleLoop] drop writeout package{%#v}", outPkg)
 			}
 
-		case <-wheel.After(s.period):
+		case <-time.After(s.period):
 			if flag {
 				if wsFlag {
 					err := wsConn.writePing()